The 50 most-cited articles in The Analyst, 2022

for the tea leaves. Quasi-spherical particles and irregular fragments dominate the shape of microplastics in beer and mineral water, whereas tea leaves carry numerous microplastic fibers. By identification through Raman spectroscopy, we observed the presence of polystyrene (PS) and polypropylene (PP) microplastics in beers, PP in bottled mineral water, and polyethylene (PE) and polyethylene terephthalate (PET) in tea leaves. Possible contamination sources include raw materials, atmosphere, and tools and containers that release microplastics. Given the facile adsorption of heavy metals and antibiotics to microplastics in beverages, public concern may arise regarding the accumulation of microplastics through the food chain and their synergetic harmful effect. Thus, our results should inspire further efforts that may contribute to the elimination and removal of microplastics from foods.

Scientific investigation of cultural heritage objects plays a vital role in a responsible modern approach to conservation and archaeology. Recent advances in spectroscopy, such as the development of Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and ATR-FTIR spectroscopic imaging, have opened up a window of opportunities for characterisation of materials in artefacts and collections from museums. This review summarises some of the recent advances and applications of these ATR-FTIR spectroscopic analytical techniques in the area of cultural heritage studies, including examples of cross-sections of oil paintings, paper, textiles, plastic objects, potteries, glasses and mineral artefacts. Two of the major advantages of ATR mode measurements are minimal or no requirements for sample preparation and its provision for high lateral spatial resolution. In addition to conventional single point detection, two-dimensional mapping and imaging is especially beneficial for chemical visualisation of multi-layered structure cultural objects. This review also explores…

Nanozymes have been widely used to construct colorimetric sensors due to their advantages of cost-effectiveness, high stability, good biocompatibility, and ease of modification. The emergence of nanozymes greatly enhanced the detection sensitivity and stability of the colorimetric sensing platform. Recent significant research has focused on designing various sensors based on nanozymes with peroxidase-like activity for colorimetric analysis. However, with the deepening of research, nanozymes with peroxidase-like activity has also exposed some problems, such as weak affinity and low catalytic activity. In view of the above issues, existing investigations have shown that the catalytic properties of nanozymes can be improved by adding surface modification and changing the structure of nanomaterials. In this review, we summarize the recent trends and advances of colorimetric sensors based on several typical nanozymes with peroxidase-like activities, including noble metals, metal oxides, metal sulfides/metal selenides, and carbon and metal-organic frameworks (MOF). Finally, the current…

Surface enhanced Raman scattering (SERS) is a powerful spectral analysis technique and has exhibited remarkable application prospects in various fields. The design and fabrication of high-performance SERS substrates is key to promoting the development of SERS technology. Apart from noble metal substrates, non-metal substrates based on semiconductor materials have received increasing attention in recent years owing to their unique physical, chemical, and optical properties. However, compared with noble metal substrates, most semiconductor substrates show weak Raman enhancement ability. Therefore, exploring effective strategies to improve the SERS sensitivity is an urgent task. Numerous reviews have outlined the research progress of semiconductor SERS substrates, which mainly focused on summarizing the material category of semiconductor substrates. However, reviews that systematically summarize the strategies for improving the SERS performance of semiconductor substrates are lacking. In this review, we comprehensively discuss the research on semiconductor SERS from the aspects of…

. In addition, the flexible sensor shows high stability and a good electrochemical response to glucose when stretched and bent to different levels. Moreover, it maintained long-term stability and high selectivity for glucose monitoring. Lastly, a sweat-absorbent cloth was used to cover the working area of the sensor and was fixed with a needle and thread to form a wearable sweat glucose sensor. The sensor can be attached to the skin for stable, accurate and continuous monitoring of glucose levels in human sweat for one day. This work validates the potential of our high-performance wearable sensor for out-of-clinic health monitoring.

Single-cell manipulation and analysis is critical to the study of many fundamental biological processes and uncovering cellular heterogeneity, and presents the potential for extremely valuable applications in biomedical fields, including neuroscience, regenerative therapy, early diagnosis, and drug screening. The use of microfluidic technologies in single-cell manipulation and analysis is one of the most promising approaches and enables the creation of innovative conditions that are impractical or impossible to achieve using conventional methods. Herein, an overview of the technological development of single-cell droplet microfluidics is presented. The significant advantages of microfluidic droplet technology, the dynamic parameters affecting droplet production, and the geometric structures of microfluidic devices are emphasized. Furthermore, the progress to date in passive and active droplet generation methods based on microfluidics and various microfluidic tools for the production of single-cell droplets and hydrogel microspheres are summarized. Their key features, achievements,…

The illegal addition of melamine to dairy products and the contamination of water with Hg 2+ are serious threats to human health. This necessitates the search for new and efficient probe for detection of melamine in foods and Hg 2+ in water samples.

Interstitial skin fluid (ISF) is an emerging alternative source of blood samples that has attracted great interest from researchers. It is a very promising way to use microneedle patches for extracting ISF. However, the recovery of ISF still faces great challenges, such as long extraction time and low extraction volume, which may affect the analysis of biomarkers. Traditional centrifugation methods cannot completely recover ISF, which leads to inaccuracy in ISF detection. In this paper, the prepared polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) microneedle patches had the ability to insert into the skin in a dry state; at the same time, the microneedle patches had good swelling properties and could extract ISF in a short time without any additional devices. Due to the thermal degradation of PVA, the way of gentle heating was used to recover ISF, which could greatly improve the accuracy of detection. By comparing the D-glucose content assay kit with the blood glucose concentration of rats detected using a commercial glucometer, the detection accuracy of the microneedle patches was…

bioimaging, photodynamic therapy (PDT), and photothermal therapy (PTT). Based on the latest scientific achievements, the advantages and disadvantages of UCNPs in biomedical and optical applications are also discussed to overcome the shortcomings and to improve the future study directions. This review delivers beneficial practical information of UCNPs in the past few years, and insights into their research in various fields are also discussed precisely.

Proteins are the key biological actors within cells, driving many biological processes integral to both healthy and diseased states. Understanding the depth of complexity represented within the proteome is crucial to our scientific understanding of cellular biology and to provide disease specific insights for clinical applications. Mass spectrometry-based proteomics is the premier method for proteome analysis, with the ability to both identify and quantify proteins. Although proteomics continues to grow as a robust field of bioanalytical chemistry, advances are still necessary to enable a more comprehensive view of the proteome. In this review, we provide a broad overview of mass spectrometry-based proteomics in general, and highlight four developing areas of bottom-up proteomics: (1) protein inference, (2) alternative proteases, (3) sample-specific databases and (4) post-translational modification discovery.

Selectivity is one of the most crucial figures of merit in trace gas sensing, and thus a comprehensive assessment is necessary to have a clear picture of sensitivity, selectivity, and their interrelations in terms of quantitative and qualitative views. Recent reviews on gas sensors/techniques are limited to specific sensors, sensors with unconventional materials, various technological exploitation, or specific applications. However, the selectivity is either unexplored in most cases or explained concerning the materials/techniques involved in a demonstration. Therefore, there is a pressing need to identify the possible ways to improve the selectivity of a gas sensor/technique with low or zero cross-sensitivity to other compounds/gases present in the working environment. Analytical techniques involving spectroscopic and mass-spectrometry-based methods are excellent in selectivity but have limited applicability for field deployment compared to the miniatured solid state sensors. Solid state sensors are the mainly studied gas sensors due to their flexibility, portability, and…

Electrochemical (bio)sensors are considered clean and powerful analytical tools capable of converting an electrochemical reaction between analytes and electrodes into a quantitative signal. They are an important part of our daily lives integrated in various fields such as healthcare, food and environmental monitoring. Several strategies including the incorporation of porous carbon materials in its configuration have been applied to improve their sensitivity and selectivity in the last decade. The porosity, surface area, graphitic structure as well as chemical composition of materials greatly influence the electrochemical performance of the sensors. In this review, activated carbons, ordered mesoporous carbons, graphene-based materials, and MOF-derived carbons, which are used to date as crucial elements of electrochemical devices, are described, starting from their textural and chemical compositions to their role in the outcome of electrochemical sensors. Several relevant and meaningful examples about material synthesis, sensor fabrication and applications are illustrated and…

Rolling circle amplification (RCA) is a simple and isothermal DNA amplification technique that is used to generate thousands of repeating DNA sequences using circular templates under the catalysis of DNA polymerase. Compared to alternating temperature nucleic acid amplification such as polymerase chain reaction (PCR) amplification, RCA is more suitable for on-spot detection without the need for an expensive thermal cycler. In this study, the principle and classification of RCA are introduced, and the applications of RCA in the detection of pathogenic bacteria, nucleic acid tumor markers, viruses, and proteins are reviewed. Finally, the perspectives of RCA in biological detection are anticipated. The RCA method has a great potential for biological detection. This review aims to provide references for the further development and application of the RCA technique in biosensors.

Fish-based food products play important roles in our daily diet. The related food safety is vitally essential for human health, thus it is very necessary to screen the freshness of fish-based foods. In this work, we presented a ratiometric fluorescent probe PTCN for the determination of cadaverine, a metabolic biomarker of the spoilage of fish. PTCN displayed a ratiometric fluorescence response towards cadaverine with good specificity, high sensitivity (LOD = 46 nM) and ultra-fast response (<15 s), and thus has been successfully utilized to determine cadaverine from the spoilage of fish. PTCN was fabricated into cheap and portable sensing tags, which can visually detect gaseous cadaverine with obvious fluorescence color transformation from red to green and a low detection limit (8.65 ppm). Moreover, the PTCN tags were used as smart fluorescent tags for non-contact and visual monitoring of cadaverine in fish. Furthermore, the ratiometric fluorescence signals were utilized to create a smartphone-adaptable digital sensing profile for indicating cadaverine in fish products.

(S/N = 3). In the analysis of artificial saliva and human serum samples, the proposed SPR biosensor exhibits good reproducibility and high specificity, which indicates its potential for application in complex bodily fluids. The exploitation of the MXene-based SPR biochip for recognizing the SARS-CoV-2 antigen provides an accessible and rapid way for COVID-19 diagnosis, and promotes the application of 2D nanomaterial-based sensing chips in clinical diagnosis and disease screening. Significantly, the proposed method possesses general applicability that can be reprogrammed to detect any protein antigen if a corresponding specific nanobody is available.

infrared, Raman, and mass spectroscopy, have baseline drifts due to fluorescence or other reasons, which have an adverse impact on subsequent analyses. Therefore, several researchers have proposed the use of various baseline-correction methods to address the aforementioned issue. However, most baseline-correction methods require manual adjustment of the parameters to achieve desirable performance. In this study, we propose a baseline-correction method based on a deep-learning model that combines ResNet and UNet. The method uses a deep-learning model trained with simulated spectral data to perform baseline corrections and eliminates the need for manual parameter adjustments. Based on the results of the qualitative and quantitative analyses of the simulated spectral data and actual Raman spectra, the proposed method is easier to apply and has better performance compared to the existing methods. As the proposed method can be applied to Raman spectra and other spectra, it is expected to be widely used.

), reactive oxygen species, and methylglyoxal). To this end, a great number of small molecular fluorescent probes with good water solubility, blood-brain barrier crossing capability, and ease in tuning photophysical and biological properties have been studied for the AD diagnosis. Herein, we systematically update the progress of NIRF AD probes in the last three years. The special focus is on the mechanisms for the targeted diagnosis and the relationship between the structure and properties of the probes. Importantly, NIRF probes with complementary functions such as dual-responsiveness and multimodal imaging and even therapeutics are discussed. Moreover, the challenges and perspectives of the AD probes are briefly elucidated. We hope that this review provides guidance for researchers and expedites the preclinical and clinical study of the NIRF AD probes.

Compared to ordinary cells, tumor cells have a unique microenvironment, characterized by high viscosity, low pH, high reactive oxygen species level and the overexpression of certain proteases. Therefore, viscosity and pH can be used as important parameters for visualizing cancer. We designed a spiro-oxazolidine compound (In-1) for the dual-channel detection of viscosity and pH, with the red channel for detecting viscosity and the blue channel for pH. Interestingly, In-1 can locate different organelles under different conditions. Under physiological conditions, In-1 efficiently targeted lysosomes and showed that the viscosity of lysosomes increases in cancer cells while the pH decreases, which can be used to distinguish and detect cancer cells and normal cells. When we treated HL-7702 cells with CCCP, the probe could effectively target the mitochondria, and the fluorescence intensity in the pH channel decreased. This indicates that In-1 can be used as a powerful tool to simultaneously monitor viscosity and pH in different organelles, and may have a guiding role in diseases caused by…

the Fe-PDA nanozyme and oxidize colorless TMB to blue oxTMB with absorbance at 653 nm. The absorbance at 653 nm expressed a clear linear relationship with hypoxanthine concentration in the range of 5.13-200 μM, and the detection limit was 1.54 μM. This method was further assessed by measuring the recovery of Hx added to meat samples, which showed promising accuracy. Overall, the developed Fe-PDA nanozyme with excellent peroxidase-mimicking activity is cost-effective, high-performance and easy to produce, offering an efficient and low-cost sensing system based on spectrophotometry for meat freshness determination as an alternative to conventional methods.

, respectively, which are two orders of magnitude lower than their concentrations in blood. Compared with the existing detection technology, SERS-LFA has the advantages of high specificity, high sensitivity, low cost, multiple detection, and rapid detection. Therefore, SERS-LFA has a broad application prospect in the early diagnosis and monitoring of AD in the future.

). This review provides a comprehensive view of the current state of the art with regard to using SERS for assessing antibiotic resistance with a future outlook on where the field go head in the coming years.

Stimulated Raman scattering (SRS) microscopy provides rapid label-free 3D chemical imaging with wide-ranging applications including histology, pharmacokinetic studies, and materials characterisation. SRS microscopy has seen a steady increase in utilisation since the early 2000s and has become more accessible due to the increase in availability of facilities, and the development of user-friendly instrumentation. Although some complete SRS systems are now commercially available, many instruments are home-built with highly varied laser sources, optics, and detection mechanisms. Signal intensity is also dependent on the effective spatiotemporal overlap of two (or more) laser beams, thus any drift in alignment can result in variable performance. Currently there is a lack of standard procedures or reference materials for SRS, which has important implications on reproducibility and consistency. These concerns are particularly relevant to the comparison of data from the same instrument at different times and instrument settings as well as between different instruments and laboratories. This…

Rapid, simple, inexpensive, accurate and sensitive point-of-care (POC) detection of viral pathogens in bodily fluids is a vital component of controlling the spread of infectious diseases.

= 3). We suggest that this low-cost and simple electrochemical paper-based device could be an alternative tool for detecting disease-specific exosomes in biological samples with the potential to be further developed for point-of-care diagnosis.

Bacterial infection is a common impediment towards wound healing. Detecting bacterial infections is important to promote wound healing and curb chronic non-healing wounds. In this review, we firstly discuss bacterial communities, including aerobic and anaerobic bacteria in various types of wounds. Following the discussion of wound sampling methods (swab, biopsy) for different wounds, we then discuss laboratory based conventional methods (bacteria cultures, Gram staining, analytical profile index systems, polymerase chain reaction, and gas chromatography coupled with mass spectrometry), focusing on their recent improvement. After that we discussed the contemporary biosensor methods, including e-Nose, electrochemical sensors, surface enhanced Raman spectroscopy, and nucleic acid lateral flow immunoassay. Biosensors embedded into wound dressing, termed wearable sensors or smart wound dressing, are also discussed for their ability of enabling bacteria detection directly from wound sites without the need for obtaining swab/biopsy samples. We have compared all the detection methods for…

microenvironment. This review provides an overview of the advantages of 3D spheroid cultures with a summary of the recent applications for tumour microenvironment-focused cellular interactions, as well as the studies on spheroids and external stimuli. These 3D tumour spheroid-based microfluidic devices will provide a platform for a better understanding of cellular and external interactions, as well as the discovery of cancer therapeutics.

Biomass materials have abundant natural resources, renewability and good biochemical compatibility, so biomass-based fluorescent materials prepared from biomass materials have gradually become a research hotspot.

Recent progress in biointerface research has highlighted the role of antifouling functionalizable coatings in the development of advanced biosensors for point-of-care bioanalytical and biomedical applications dealing with real-world complex samples. The resistance to nonspecific adsorption promotes the biorecognition performance and overall increases the reliability and specificity of the analysis. However, the process of modification with biorecognition elements (so-called functionalization) may influence the resulting antifouling properties. The extent of these effects concerning both functionalization procedures potentially changing the surface architecture and properties, and the physicochemical properties of anchored biorecognition elements, remains unclear and has not been summarized in the literature yet. This critical review summarizes these key functionalization aspects with respect to diverse antifouling architectures showing low or ultra-low fouling quantitative characteristics in complex biological media such as bodily fluids or raw food samples. The subsequent…

particles per mL. In addition, this method can detect exosomes in complex fetal bovine serum samples with good specificity and high sensitivity toward exosomes from breast, liver, and lung cancers with abnormal EpCAM protein expression.

) decreases as the overall WE size increases. On the other hand, these four WE shapes were applied toward the well-known and benchmarking detection of ascorbic acid (AA), uric acid (UA), β-nicotinamide adenine dinucleotide (NADH) and dopamine (DA). Moreover, electroanalytical detection of real acetaminophen (ACOP) samples is also showcased. The different designs for the working electrode proposed in this manuscript are easily changed to any other desired shapes thanks to the additive manufacturing methodology, these four shapes being just an example of what additive manufacturing can offer to experimentalists and to electrochemists in particular. Additive manufacturing is shown here as a versatile and rapid prototyping tool for the production of novel electrochemical sensing platforms, with scope for this work to be able to impact a wide variety of electroanalytical applications.

The human body secretes a complex blend of volatile organic compounds (VOCs) via the skin, breath and bodily fluids, the study of which can provide valuable insight into the physiological and metabolic state of an individual. Methods to profile human-derived volatiles typically source VOCs from bodily fluids, exhaled breath or skin of isolated body parts. To facilitate profiling the whole body volatilome, we have engineered a sampling chamber that enables the collection and analysis of headspace from the entire human body. Whole body VOCs were collected from a cohort of 20 humans and analyzed by thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) to characterize the compounds present in whole body headspace and evaluate chemical differences between individuals. A range of compounds were detected and identified in whole body headspace including ketones, carboxylic acids, aldehydes, alcohols, and aliphatic and aromatic hydrocarbons. Considerable heterogeneity in the chemical composition of whole body odor and the concentration of its constituent compounds was observed…

flow rate) have shown almost 100% motility, a significantly higher percentage of morphologically normal sperm cells with lesser sperm DNA fragmentation than the control (no-flow) and raw semen sample. This chip satisfies the need of a clinical setting as it is low-cost, easy to operate and uses a small semen volume for sperm sorting.

showed that GSH and PG within a certain concentration not only did not affect the hatchability, survival rate and teratogenic rate of zebrafish embryos, but also can significantly inhibit melanin formation in zebrafish embryos. The results of this study have an important guiding significance for the dosage of antioxidants used in the cosmetics and food industries.

Electrochemiluminescence (ECL) is produced by chemiluminescence reactions initiated by electrochemical methods. On this basis, ECL microscopy (ECLM) is an emerging visualization tool to directly study local electrochemical features with good spatial and temporal resolution. Recent progress in ECLM demonstrates that it is particularly important in single-cell studies on the morphological structures and functional characteristics of cells due to the unique heterogeneity of cells. Compared with other single-cell imaging methods, ECLM possesses advantages such as a low optical background, high sensitivity, simple instrumentation and surface-confined mode. In this mini-review, we discuss the recent development of single-cell ECLM and classify these works according to different ECL routes. Because ECL routes significantly influence the features of ECLM, such as the thickness of the emitting layer and the brightness of emitters, it is necessary to provide a new insight to revisit these works and discuss what ECL routes can be chosen to study single-cell processes from different…

Flow cytometry has proven its capability for rapid and quantitative analysis of individual cells and the separation of targeted biological samples from others. The emerging microfluidics technology makes it possible to develop portable microfluidic diagnostic devices for point-of-care testing (POCT) applications. Microfluidic flow cytometry (MFCM), where flow cytometry and microfluidics are combined to achieve similar or even superior functionalities on microfluidic chips, provides a powerful single-cell characterisation and sorting tool for various biological samples. In recent years, researchers have made great progress in the development of the MFCM including focusing, detecting, and sorting subsystems, and its unique capabilities have been demonstrated in various biological applications. Moreover, liquid biopsy using blood can provide various physiological and pathological information. Thus, biomarkers from blood are regarded as meaningful circulating transporters of signal molecules or particles and have great potential to be used as non (or minimally)-invasive diagnostic…

electrochemical polymerization with the safe chemical DA as the polymerization monomer and the uncontrolled pharmaceutical intermediate 3,4-methylenedioxyphenethylamine (MDPEA) as the template molecule, which can provide a great quantity of specific binding sites and expand the practical application of the sensor. Due to the superior affinity of MIP@PDA to the target, the proposed sensor displayed excellent analytical performance, with LODs of 37 nM and 54 nM for the determination of MDA and MDMA, respectively. Additionally, this sensor presented suitable selectivity, stability, reproducibility and detection ability in practical urine samples, which suggested that it is a promising candidate as a rapid diagnostic method in drug investigations.

M, which is more sensitive than other reported cortisol analysis methods. In addition, this sensor can realize the determination of cortisol in salivary samples with high recovery values, showing great development potential in the field of life sciences.

, thereby covering the reference range for G-17. Serum samples were used to validate the test strip, which exhibited high sensitivity, high specificity, and consistency with the results obtained by the enzyme-linked immunosorbent assay method. The entire inspection process using this method can produce results within 35 min and it is simple to operate without requiring strict experimental conditions. This dual-mode lateral flow test strip provides a simple, rapid, and quantitative strategy for detecting G-17, and it may also be valuable in other portable diagnostic applications.

Solution-based SERS detection by using a portable Raman instrument has emerged as an important tool due to its simplicity, and flexibility for rapid and on-site screening of analyte molecules. However, this method has several shortcomings, including poor sensitivity especially for weak-affinity analyte molecules, where there is no close contact between the plasmonic metal surface and analyte molecule. Examples of weak-affinity molecules include pigment molecules that are commonly used as a consumable coloring agent, such as allura red (AR), and sunset yellow (SY). As high consumption of colorant agents has been shown to cause adverse effects on human health, there is a strong need to develop a simple and practical sensing system with high sensitivity for these agents. Here we present a novel, highly sensitive solution-based SERS detection method for AR, and SY by using CTAC capped gold nanostars (GNS) having different aspect ratios (GNS-2, GNS-4, and GNS-5) without utilizing any aggregating agents which can enhance SERS signal however it reduces batch to batch reproducibility. The…

Endoplasmic reticulum (ER) is an indispensable organelle in eukaryotic cells involved in protein synthesis and processing, as well as calcium storage and release. Therefore, maintaining the quality of ER is of great importance for cellular homeostasis. Aberrant fluctuations of bioactive species in the ER will result in homeostasis disequilibrium and further cause ER stress, which has evolved to contribute to the pathogenesis of various diseases. Therefore, the real-time monitoring of various bioactive species in the ER is of high priority to ascertain the mysterious roles of ER, which will contribute to unveiling the corresponding mechanism of organism disturbances. Recently, fluorescence imaging has emerged as a robust technique for the direct visualization of molecular events due to its outstanding sensitivity, high temporal-spatial resolution and noninvasive nature. In this review, we comprehensively summarize the recent progress in design strategies, bioimaging applications, potential directions and challenges of ER-targetable small-molecular fluorescent probes.

has low redox potential. Therefore, the electrode has a linear range of 3-5166 μM for glucose detection, with a detection limit as low as 0.28 μM, showing excellent selectivity and reproducibility. The composite-modified electrode provides accurate detection results with real human serum samples, which are in full agreement with those of commercial blood glucose meters. In addition, we tested the glucose content in tea and sorghum fermentation broth at different stages, further expanding the application range of the Mn-NiO sensors. The nano-enzyme sensor fabricated herein offers a new idea for further integration into wearable flexible electronic devices for accurate glucose detection.

. Since digital MCA only requires an intercalation dye instead of sequence-specific hydrolysis probes to perform multiplex digital PCR analysis, it can be less expensive and not limited to the number of fluorescence channels.

A highly selective electrochemical sensor based on a molecularly imprinted polymer (MIP) to be developed for uric acid detection in the presence of dopamine as an interference molecule was demonstrated in this study. This non-enzymatic uric acid sensor was developed by electropolymerizing poly-pyrrole onto a composite of electrochemically reduced graphene oxide (ErGO) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on a glassy carbon electrode (GCE) to give MIP/ErGO/PEDOT:PSS electrodes. The structural properties, surface morphology, and electrochemical interface of this fabricated uric acid sensor was then characterized using infrared spectroscopy, scanning electron microscopy, atomic force microscopy, and electrochemical impedance spectroscopy. This fabricated non-enzymatic electrochemical sensor (MIP/ErGO/PEDOT:PSS modified GCE) also showed excellent analytical performance at the optimum ratio of monomer/template concentration and optimized electropolymerization conditions, for example in the low concentration range of 0.1-100 μM with a detection limit of…

) larger than 0.9662. The advantage of this method is that the neural network can extract data features from the entire SERS spectrum, which makes up for information loss when manually identifying the spectrum and selecting a limited number of characteristic peaks. This work clearly clarifies that the combination of SERS and deep learning technology has become an inevitable development trend, and also demonstrates the great potential of this strategy in the practical application of SERS.

. A reproducibility of 3.40%RSD was noted for 15 repetitive measurements. The analytical performance was found to be favourable in comparison to those of other typical electrochemical and electrochemiluminescence methods, indicating that it is applicable for real sample detection.

for APE1 and 0.25 nM for miRNA-21 and APE1, respectively, and also exhibits good selectivity and stability for the two biomarkers. Thus, the biosensor has great potential to be applied as a new platform for cancer diagnosis.

The fabrication of nanopores with a matched pore size, and the existence of multiple interferents make the reproducible detection of small-sized molecules by means of solid-state nanopores still challenging. A useful method to solve these problems is based on the detection of large DNA nanostructures related to the existence of small-sized targets. In particular, a DNA tetrahedron with a well-defined 3D nanostructure is the ideal candidate for use as a signal transducer. Here, we demonstrate the detection of an L1-encoding gene of HPV18 as a test DNA target sequence in a reaction buffer solution, where long single-stranded DNA linking DNA tetrahedra onto the surface of the magnetic beads is cleaved by a target DNA-activated CRISPR-cas12 system. The DNA tetrahedra are subsequently released and can be detected by the current pulse in a glassy nanopore. This approach has several advantages: (1) one signal transducer can be used to detect different targets; (2) a glassy nanopore with a pore size much larger than the target DNA fragment can boost the tolerance of the contaminants and…

(S/N = 3). Furthermore, this method has been successfully applied to the analysis of actual samples with satisfactory results, which will provide a certain reference for the detection of small molecules in food and environmental analysis.

The coronavirus pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) directly or indirectly affects every individual worldwide. The fight against SARS-CoV-2 is based on the rapid and accurate diagnosis and subsequent isolation of infected individuals. Therefore, the demands for the scientific development of diagnostic methods for the confirmation of SARS-CoV-2 are enormous. Currently, reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is the main method used for detecting viruses, including SARS-CoV-2, and is considered the gold standard for coronavirus disease 2019 (COVID-19) identification. However, various alternatives have been investigated due to the time and cost demands of this method or to shortages of reagents. In this review, we focus on matrix-assisted laser desorption and ionisation with time-of-flight analyser mass spectrometry (MALDI-TOF MS) techniques as potential tools for the diagnosis of viruses with an emphasis on SARS-CoV-2. MALDI-TOF is commonly used in clinical laboratories for bacterial characterization and…

) under optimal conditions. The results certified that the constructed sensor had high selectivity, excellent reproducibility and good stability, and had been used successfully for DA detection in actual human serum samples.