Simultaneous Detection Research Articles

Micro-biosensor fabrication by microfluidic channel for simultaneous detection of choline and creatine

Choline, and creatine are two common metabolites in the nervous system, and dysregulation in choline and creatine levels is associated with the development and recurrence of glioma. In this paper, we developed an enzymatic micro-biosensor for real-time combined sensing of choline and creatine. We simulated the influence of enzyme layer thickness and electrode spacing on the electrode work with COMSOL software, then employed microfluidic channels to immobilize an enzyme layer with a precise extent. And the sensor worked with this technique to transfer and pattern choline oxidase (ChOx) and the mixture of creatinase (Cr) and sarcosine oxidase (SO) onto targeted sites on microelectrode arrays (MEA). The combined sensing micro-biosensor was confirmed that it has high sensitivity for choline and creatine with 208 and 35 μA mM−1 cm−2, respectively, and also low detection limits to around 1 and 10 μM, respectively, with relative rapid response times within 10 s (≤10 s). This work demonstrates that microfluidic channels can be an efficient method for fabricating multi-analyte enzymatic micro-biosensor.

Gamma-irradiated hydroxyapatite based electrochemical sensor for simultaneous detection of rutin and quercetin flavonoids

Gamma-irradiated hydroxyapatite based electrochemical sensor for simultaneous detection of rutin and quercetin flavonoids

Research note: Simultaneous detection of GPV, H5 AIV, and GoAstV via TaqMan probe-based multiplex qPCR

The endemic status of goose parvovirus (GPV), H5 subtype avian influenza virus (AIV), and goose astrovirus (GoAstV) infections continues to devastate the poultry industry in China. Despite this, there exists a notable gap in the application of molecular diagnostic techniques. This investigation described the development of a multiplex qualitative polymerase chain reaction (qPCR) assay capable of concurrently detecting GPV, H5 AIV, and GoAstV, with no cross-reactivity observed with other avian viral pathogens. The assay exhibited a detection threshold of 10 copies/μL for both GPV and GoAstV, and 1 copy/μL for H5 AIV. The intra- and inter-assay coefficients of variation were < 3.0%, signifying high repeatability within and across assay batches. Utilizing this multiplex qPCR assay, a batch of 60 clinical samples was analyzed to assess its practical utility. The detected prevalence rates for GoAstV, GPV, and H5 AIV were 35.0% (21/60), 21.7% (13/60), and 15.0% (9/60), respectively. Concurrent infections were also identified, with rates for GPV + GoAstV, GPV + H5 AIV, GoAstV + H5 AIV, and GPV + GoAstV + H5 AIV being 6.7% (4/60), 3.3% (2/60), 3.3% (2/60), and 3.3% (2/60), respectively. The developed multiplex qPCR assay exhibited a diagnostic concordance rate equivalent to that of traditional PCR techniques. This novel assay serves as a rapid, efficient, specific, and sensitive tool for the detection of prevalent goose viruses, thereby enhancing disease management strategies and epidemiological monitoring efforts.

A chip-based universal strategy to realize multiplex PCR by using wax films for sealing and controllable release of primers

Simultaneous detection of multiple nucleic acid targets from a single sample is a common requirement in molecular diagnosis and basic research. Dividing a bulky polymerase chain reaction (PCR) into many isolated small reaction units through microfluidic technology is commonly used to realize this goal. However, previous microfluidic platforms for multiplex PCR suffer from complex structures and strict operation requirements. In this study, a chip-based universal strategy is constructed to realize multiplex PCR by using wax films for sealing and controllable release of prespotted primers. This microfluidic chip contains twenty-four reaction chambers connected in series by a single channel, and the bottom of each reaction chamber is covered by a wax film generated by solvent volatilization. These wax films can prevent the prespotted primers from being flushed away by the reaction mixture during the injection process. After thermal blocking of the connecting channel to isolate each reaction chamber, the chip is placed on a flat thermal cycler. The wax films melt during the denaturing step of PCR so that the primers are released and mixed with the reaction mixture, a process seamlessly compatible with PCR thermal cycling. After fluid flow simulation and carefully examining its basic performance, this chip was applied to genotype seven deafness-associated hotspot mutations using a competitive allele-specific PCR assay. The genotyping results of clinical samples using this chip were totally concordant with those obtained by Sanger sequencing, demonstrating the practical utility of this universal strategy for multiplex PCR detection.

Development of an external standard method for the high-throughput determination of broadly polar multiclass synthetic dyes in high-sugar, high-fat, and high-protein foods

Simultaneous detection of multiple synthetic dyes in food additives presents a challenge. A high-throughput UPLC-Q-OMS method with purification-free extraction was developed for the simultaneous detection of 30 synthetic dyes across six categories in various foods. The results showed satisfactory separation of the dyes was achieved using a phenyl column, acetonitrile, and a 5 mmol/L ammonium acetate mobile phase. Designing methanol-acetonitrile (2:3, v/v) as a bifunctional extractant can minimize matrix interference and enhance synergistic effects. The LODs of the method were in the range of 0.15–6.28 μg/L, the LOQs were in the range of 0.48–20.52 μg/L with good linearity, and the correlation coefficients (r2) were greater than 0.99. The recoveries at the three spiked levels were in the range of 82.6 %–106.3 %. The technique detected four synthetic dyes within regulatory limits in six out of 66 sample batches (9.09 %), demonstrating its effectiveness in addressing interference and strong applicability.

Simultaneous detection of mixed colorants adulterated in black tea based on various morphological SERS sensors

Simultaneous detection of mixed colorants adulterated in black tea based on various morphological SERS sensors

An Amplification-Free Digital Assay Based on Primer Exchange Reaction-Mediated Botryoidal-Like Fluorescent Polystyrene Dots to Detect Multiple Pathogenic Bacteria.

Multiple and ultrasensitive detection of pathogenic bacteria is critical but remains a challenge. Here, we introduce a digital assay for multiplexed and target DNA amplification-free detection of pathogenic bacteria using botryoidal-like fluorescent polystyrene dots (PS-dots), which were first prepared through the hybridization reaction between primer exchange reaction chains and polystyrene nanospheres that encapsulated polymer dots for signal preamplification. The pathogenic bacteria's DNA was cleavaged by the argonaute (Ago) protein-mediated multiple and precise cleavage reactions, where the obtained target sequences bridged the magnetic beads (MBs) and botryoidal-like PS-dots via a hybridization reaction, and the fluorescent MB-botryoidal PS-dot complexes were utilized as digital probes based on colors and sizes for digital encoding. An artificial-intelligence-fluorescent microsphere counting algorithm was applied to identify and count the fluorescent MBs for digital readout. This digital assay combined the ultrabright botryoidal-like PS-dots with Clostridium butyricum Ago's precise enzyme cleavage properties, achieving simultaneous detection of three pathogenic bacteria with a linearity range from 102 to 106 CFU/mL without target DNA amplification within 1.5 h. This digital assay has also been applied to detect aquatic and clinical samples with accepted accuracy (98%), which offers an avenue for a next-generation multiplexed digital platform for pathogenic bacteria analysis.

Simultaneous detection of novel goose parvovirus and novel duck reovirus by SYBR Green I-based duplex real-time quantitative polymerase chain reaction.

Co-infection with novel goose parvovirus (NGPV) and novel duck reovirus (NDRV) is common, significantly impeding duck growth and resulting in considerable economic losses within the duck farming industry. To facilitate rapid and accurate diagnosis and differentiation of these two viruses, this study developed a SYBR Green I-based duplex real-time quantitative polymerase chain reaction (qPCR) assay.This assay enabled the simultaneous detection of NGPV and NDRV by exploiting their distinct melting temperatures (Tm): 78.5 ± 0.50°C for NGPV and 84.5 ± 0.50°C for NDRV. No amplification was observed for other prevalent non-target duck viruses. The intra- and inter-assay coefficients of variation were less than 1.75%. The assay showed good performance with the same detection limit of 102 copies/μL for both NGPV and NDRV. The results of the clinical testing indicated that 45.3% (34/75) of the samples tested positive for NGPV, while 38.7% (29/75) were positive for NDRV. Notably, 13.3% (10/75) exhibited co-infection. These results revealed that the sensitivity of the developed method exceed that of conventional polymerase chain reaction (PCR). The developed method for the identifying of NGPV and NDRV shows good specificity, sensitivity, and repeatability, rendering it an effective tool for the simultaneous detection of co-infection with NGPV and NDRV.

Carbon dots modified hydrange-shaped ZnCo(OH)F used as a flexible electrode for sensitive detection of dopamine and uric acid

Dopamine (DA), widely recognized as the most prevalent catecholamine neurotransmitter in the brain, functions as a vital regulator of various physiological processes within the central nervous system. Meanwhile, uric acid (UA) serves as the terminal product of purine metabolism, and hyperuricemia emerges as a significant risk factor for gout, with a steep escalation in risk as blood uric acid levels surge. Consequently, monitoring the concentrations of DA and UA in biological fluids is crucial not only for the treatment of related disorders but also for enhancing disease prevention strategies. In this work, the blooming hydrangea shaped ZnCo(OH)F/carbon dots (CDs) composite was grown on carbon cloth (CC) substrate by a simple hydrothermal method, which was used as a flexible sensor for the detection of DA and UA. The unique open structure and morphologic adjustment strategy of ZnCo(OH)F/CDs/CC provided a large surface area and highly exposed active site. After screening the experimental variables that affect the sensor performance, the optimal ZnCo(OH)F/CDs/CC flexible electrode achieved individual and simultaneous detection for DA and UA in the concentration ranges of 1.0220.0µM and 1.0500.0µM, the detection limits (LOD) of DA and UA were 0.0129 and 0.044μM, respectively (S/N=3). In addition, the sensor exhibited good repeatability, stability and selectivity, realizing the detection of DA and UA in human serum with recovery rate of 95.20% 105.3%. Also, the density functional theory (DFT) calculations were used to explore the interaction between electrode material and detected substrate. A simple hydrothermal method was utilized to grow the ZnCo(OH)F/CDs composite onto the CC substrate. The presence of F− in ZnCo(OH)F can increase the charge mobility and improve the conductivity. ZnCo(OH)F/CDs/CC as flexible electrode material can determine DA and UA simultaneously in human serum with a satisfactory recovery rate. This flexible sensor has a broad application prospect in the manufacture of wearable devices.

Dual-functional ratiometric fluorescence sensor based on silica spheres for highly selective detection of Hg2+ and Fe3+

Ratiometric fluorescence sensors, which validate the absence of ambient and excitation light intensity effects, have attracted significant attention. In this study, a novel nanohybrid dual-emission system was fabricated by combining nitrogen-doped carbon quantum dots (NCQDs) with 8-hydroxyquinoline (8-HQ). This system allows for the simultaneous detection of Fe3+ and Hg2+ ions by utilizing distinct signals. A ternary hollow structure nanosensor containing core-shell silica spheres modified by 8-HQ molecules and decorated with carbon quantum dots was fabricated by subsequent solvothermal synthesis. The designed nanohybrid emits dual-emission fluorescence peaks at 480 and 340nm, originating from the intrinsic structure of NCQDs and 8-hydroxyquinoline, respectively. When Hg2+ is present, only the fluorescence intensity at 480nm is noticeably reduced. However, in the presence of Fe3+ ions, the fluorescence intensity at 480nm remains mostly unchanged, but clear fluorescence quenching is detected at 340nm. There was a linear relationship between fluorescence intensity ratios at 340 and 480nm and the concentration of Hg2+ and Fe3+, with detection limits of 9.50nM and 0.96μM, respectively. Furthermore, it demonstrated satisfactory assay performance in quantifying the mercury content in amalgam alloy and the Fe3+ concentration in a water sample. The results of this study offer a new approach to designing multifunctional fluorescent sensors and a potential application for biomedicine and environmental monitoring.

Simultaneous Analysis of 504 Pesticide Multiresidues in Crops Using UHPLC-QTOF at MS1 and MS2 Levels.

A robust analytical method was developed for the simultaneous detection of 504 pesticide multiresidues in various crops using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF). The method integrates both MS1 and MS2 levels through sequential window acquisition of all theoretical mass spectra (SWATH) analysis, allowing for accurate mass measurements and the construction of a spectral library to enhance pesticide residue identification. An evaluation of the method was carried out according to international standards, including the FAO guidelines and SANTE/11312/2021. Validation across five representative crops-potato, cabbage, mandarin, brown rice, and soybean-demonstrated exceptional sensitivity, with over 80% of the analytes detected at trace levels (≤2.5 μg/kg). Moreover, an impressive 96.8% to 98.8% of the compounds demonstrated LOQs of ≤10 μg/kg. Most compounds exhibited excellent linearity (r2 ≥ 0.980) and satisfactory recovery rates at spiking levels of 0.01 and 0.1 mg/kg. Among 42 crop samples analyzed, pesticides were detected in 1 cabbage, 3 mandarin, and 6 rice samples, with a mass accuracy within ±5 ppm and a Fit score ≥ 70.8, confirming the method's practical applicability and reliability. The detected residues ranged from 12.3 to 339.3 μg/kg, all below the established maximum residue limits (MRLs). This comprehensive approach offers an efficient, reliable, and scalable solution for pesticide multiresidue monitoring, supporting food safety programs and regulatory compliance.

Chromoionophores decorated silica-polymer hybrid monolith as the solid-state optical sensor for the simultaneous detection of Pb2+, Hg2+, and Cd2+ in aqueous and cigarette samples

This work reports on fabricating a flexible and reliable three-in-one solid-phase ocular sensor to perceive and confiscate the trace Pb2+, Hg2+, and Cd2+ using a structurally customized probe-anchored porous hybrid monolithic sensor. The dual combination of silica/polymer hybrid monolith was achieved from the bulk polymerization of 3-(trimethoxysilyl) propyl methacrylate (TSPM) and pentaerythritol trimethacrylate (PETMA), i.e., poly(TSPM-co-PETMA). The monolithic template delivered a well-ordered porous structure and greater surface area that enabled the regular impregnation of chromophoric probe (TAN), i.e., (E)-1-(thiazol-2-yldiazenyl) naphthalene-2-ol onto monolith surface for sensing target analytes under lower ppb levels. FE-SEM, HR-TEM, EDAX, SAED, p-XRD, FT-IR, TGA and N2 isotherm were deployed to characterize the structural and exterior topographies of the hybrid sensor. The geometrically frozen TAN molecules onto the hybrid monolith form a charge transfer complex with the target ions, thereby rendering a consecutive color shift from light orange to brown for Pb2+, reddish maroon for Hg2+, and purplish pink for Cd2+. The sensor offered a linear response with metal ion concentrations ranging from 0.2 to 100 ppb with lower detection limit values of 0.42, 0.50, and 0.48 ppb for Pb2+, Hg2+, and Cd2+, respectively. The hybrid sensor affords distinct ion sensitivity and selectivity towards Pb2+, Hg2+, and Cd2+ with a quick response time of ≤ 80 s of contact. Furthermore, the sensor was tested with natural samples like environmental water and cigarette samples to validate the method’s real-time monitoring ability. The resultant statistical data demonstrated that the proposed colorimetric sensor was renewable and more feasible for practical application.

Single-Molecule-Based, Label-Free Monitoring of Molecular Glue Efficacies for Promoting Protein-Protein Interactions Using YaxAB Nanopores.

Modulating protein-protein interactions (PPIs) is an attractive strategy in drug discovery. Molecular glues, bifunctional small-molecule drugs that promote PPIs, offer an approach to targeting traditionally undruggable targets. However, the efficient discovery of molecular glues has been hampered by the current limitations of conventional ensemble-averaging-based methods. In this study, we present a YaxAB nanopore for probing the efficacy of molecular glues in inducing PPIs. Using YaxAB nanopores, we demonstrate single-molecule-based, label-free monitoring of protein complex formation between mammalian target of rapamycin (mTOR) and FK506-binding proteins (FKBPs) triggered by the molecular glue, rapamycin. Owing to its wide entrance and adjustable pore size, in combination with potent electro-osmotic flow (EOF), a single funnel-shaped YaxAB nanopore enables the simultaneous detection and single-molecule-level quantification of multiprotein states, including single proteins, binary complexes, and ternary complexes induced by rapamycin. Notably, YaxAB nanopores could sensitively discriminate between the binary complexes or ternary complexes induced by rapamycin and its analogues, despite the subtle size differences of ∼122 or ∼116 Da, respectively. Taken together, our results provide proof-of-concept for single-molecule-based, label-free, and ultrasensitive screening and structure-activity relationship (SAR) analysis of molecular glues, which will contribute to low-cost, highly efficient discovery, and rational design of bifunctional modality of drugs, such as molecular glues.

Dual-Fluorescent Quantum Dot Nanobead-Based Lateral Flow Immunoassay for Simultaneous Detection of C-Reactive Protein and Procalcitonin.

Simultaneous detection of C-reactive protein (CRP) and procalcitonin (PCT) at the point of care is crucial for the management of infections in patients with inflammation and in critical care settings. The challenge of detecting high concentrations of CRP alongside low concentrations of PCT in plasma from inflammatory patients has limited the clinical application of multiplexed immunoassays. Herein, we developed a lateral flow immunoassay (LFIA) that employs quantum dot nanobeads (QDNBs) of varying sizes and colors to enable the simultaneous quantification of PCT and CRP in human plasma. To extend the dynamic range of CRP detection, we combined QDNBs with smaller particle sizes with the CRP detection antibodies, thereby increasing the assay's dynamic range and reducing the hook effect. At the same time, the stronger fluorescence emitted by these larger QDNBs, in conjugation with the PCT detection antibodies, allows for the detection of PCT at the nanogram level, meeting the demand for high sensitivity. The results show that this method can detect CRP concentrations from 0.1 to 3 mg/L and PCT with a detection limit of 0.09 ng/mL, which is on par with clinically used methods. By employing this dual-color and dual-size QDNB labeling strategy, we successfully achieved simultaneous detection of CRP with a broad dynamic range and PCT with high sensitivity in a one-step point-of-care rapid test.

SERS calibration substrate with a silent region internal standard for reliable simultaneous detection of multiple antibiotics in water

As the extensive use of antibiotics has led to the rapid spread of antibiotic resistance, there is an urgent need for quantitative assessment of antibiotic residues in the environment. Surface-enhanced Raman spectroscopy (SERS) has emerged as a rapid and cost-effective detection method, but it suffers from the high variability in signal intensities, its quantitative detection remains challenging. Herein, we have developed a SERS calibration substrate with a silent region internal standard, enabling simultaneous and reliable quantitative detection of three commonly antibiotics of penicillin potassium (PP), tetracycline hydrochloride (TCH) and levofloxacin (LEV). The calibration substrate is made by assembling Au @ 4-mercaptobenzonitrile (4-MBN) @ SiO2 on silicon wafer. The chemically-inert silica shell allows the substrate to remain SERS active for more than 24 weeks in the air. The vC ≡ N of 4-MBN in the silent region of 1800–2800 cm−1 provides an effective reference for correcting Raman signal fluctuations. The relative SERS intensity by normalizing to the internal standard (IS) of vC ≡ N shows a linear response against to the logarithmic concentration with a correlation coefficient of 0.997, 0.976, 0.998 and a limit of detection (LOD) of 26.9, 28.2, 2.4 nM for PP, TCH and LEV, respectively. Furthermore, simultaneous detection and principal component analysis (PCA) of these antibiotics in lake water with a concentration range of 1–100 mg/L can achieve a sensitivity and specificity of 100 %. This novel quantitative technique of using this SERS calibration substrate shows promises as a high-throughput platform for multiple trace antibiotics analysis.

Beyond the mix: Advancements in simultaneous detection and quantification of human, dog, and cat DNA.

Animal-related crimes have increased with an increase in the number of pets worldwide, underscoring the importance of animal-related biological evidence at crime scenes. Evidence obtained in cases involving dogs and cats often includes a mixture of human and animal DNA. In this study, we developed a method using droplet digital polymerase chain reaction (ddPCR) to simultaneously identify and quantitatively detect human, dog, and cat DNA in mixed samples. HLA-DRA was chosen as a human-specific marker, OR6D7 as a dog-specific marker, and FLAI-K as a cat-specific marker. The species specificity of each target was confirmed using 14 control DNA samples from 11 mammals and 3 birds. Sensitivity tests determined the limit of detection to be 0.0008 ng/μL for human DNA and 0.00061 ng/μL for dog and cat DNA. In the mixture test, each DNA sample was independently and accurately detected in samples containing trace amounts of all three types of DNA. This study demonstrated the effectiveness of applying ddPCR to forensic case samples from dog- and cat-related incidents. We have presented a reliable method for the accurate identification and quantification of human, dog, and cat DNA simultaneously, offering possibilities for advancements in forensic DNA analysis and related fields.

Simultaneous Determination of Phenolic Pollutants based on Electrochemical Oxidation by Nanoporous Gold

Abstract Phenolic compounds, as highly toxic pollutants, can cause great harm to human beings and the environment even at very low concentrations. Therefore, the simultaneous detection of multiple phenolic pollutants is critically valuable for environmental monitoring. Here, an electrochemical sensor based on a glassy carbon electrode (GCE) modified by nanoporous gold (NPG) was successfully developed for the determination of phenolic pollutants including phenol (Ph), hydroquinone (HQ), catechol (CT), and o-nitrophenol (ONP), which realized not only the sensitive individual detection of each phenolic pollutant but also the sensitive simultaneous detection of these four phenolic pollutants. For the simultaneous detection, the limits of detection of Ph, HQ, CT, and ONP were 0.85, 0.17, 0.19, and 1.30 μM as well as the sensitivities of 0.24, 1.17, 1.08, and 0.16 μA μM−1 cm−2, respectively. Additionally, the NPG/GCE electrochemical sensor exhibited good stability and anti-interference capability. The recovery rates of Ph, HQ, CT, and ONP in seawater samples and wastewater samples ranged from 94.64% to 105.87%. These results indicated that the prepared NPG/GCE electrochemical sensor may be an ideal choice for the reliable simultaneous detection of multiple phenolic pollutants.

Online Direct Infusion Mass Spectrometry of Liquid–Liquid Extraction Phases for Metabolite and Lipid Profiling with the Direct Infusion Probe

Background/Objectives: Profiling of metabolites and lipids in biological samples can provide invaluable insights into life-sustaining chemical processes. The ability to detect both metabolites and lipids in the same sample can enhance these understandings and connect cellular dynamics. However, simultaneous detection of metabolites and lipids is generally hampered by chromatographic systems tailored to one molecular type. This void can be filled by direct infusion mass spectrometry (MS), where all ionizable molecules can be detected simultaneously. However, in direct infusion MS, the high chemical complexity of biological samples can introduce limitations in detectability due to matrix effects causing ionization suppression. Methods: Decreased sample complexity and increased detectability and molecular coverage was provided by combining our direct infusion probe (DIP) with liquid–liquid extraction (LLE) and directly sampling the different phases for direct infusion. Three commonly used LLE methods for separating lipids and metabolites were evaluated. Results: The butanol–methanol (BUME) method was found to be preferred since it provides high molecular coverage and have low solvent toxicity. The established BUME DIP-MS method was used as a fast and sensitive analysis tool to study chemical changes in insulin-secreting cells upon glucose stimulation. By analyzing the metabolome at distinct time points, down to 1-min apart, we found high dynamics of the intracellular metabolome. Conclusions: The rapid workflow with LLE DIP-MS enables higher sensitivity of phase separated metabolites and lipids. The application of BUME DIP-MS provides novel information on the dynamics of the intracellular metabolome of INS-1 during the two phases of insulin release for both metabolite and lipid classes.

Electrochemical Determination of Tinidazole and Brucine Using Poly (l‐Glutamic Acid) Modified Carbon Nanotube Paste Electrode

AbstractThis study developed an electrochemical method for the selective and sensitive detection of Tinidazole (TZ) by modifying a bare carbon nanotube paste electrode (BCNTPE) with electrochemically polymerized l‐Glutamic acid (P(L‐GA)/MCNTPE). The modified carbon nanotube paste electrode (MCNTPE) achieved optimal detection with an irreversible peak in a 0.2 M phosphate buffer solution (PBS) at pH 3.5. Characterization of both the P(L‐GA)/MCNTPE and BCNTPE was carried out using techniques such as scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and linear sweep voltammetry (LSV). The sensor effectively identified possible interferences from different metals and organic compounds, with scan rate studies indicating that the reaction was controlled by diffusion. The effects of pH and concentration variations were also thoroughly investigated. The active surface area of the P(l‐GA)/MCNTPE and BCNTPE were found to be 0.471 cm2 and 0.217 cm2 respectively. The P(l‐GA)/MCNTPE displayed excellent electrochemical properties, with a limit of detection (LOD) of 0.06 µM and a limit of quantification (LOQ) of 0.2 µM, along with good reproducibility, repeatability, and stability. This study presents a P(l‐GA) MCNTPE that significantly enhances the sensitivity and selectivity for simultaneous detection of TZ and bare carbon nanotube (BCN). The improved electroactive surface area and electron transfer dynamics demonstrate its potential for practical applications in pharmaceutical analysis.

Probe-based dual-chip digital loop-mediated isothermal amplification for the simultaneous detection of Staphylococcus aureus and Salmonella enteritidis in livestock and aquatic products

Staphylococcus aureus and Salmonella are common pathogens causing foodborne diseases, posing a serious threat to food safety. Accurate detection of foodborne pathogens is particularly critical. This study developed a probe-based dual-chip digital loop-mediated isothermal amplification (cdLAMP) technique that enables the simultaneous detection of Staphylococcus aureus and Salmonella in food samples. The chip contains 20,000 wells, each with a micro-reaction unit volume of approximately 1 nL. The dual-detection is achieved through the dual-color fluorescence channel equipped on the imaging analyzer. Compared with qPCR, the cdLAMP demonstrates superior sensitivity. In the detection of pure cultures and spiked food samples, the detection limit of two foodborne pathogens is 2 CFU/mL. In the detection of field samples, it is capable of detecting single colonies of both pathogens. The dynamic detection range spans 5 logs. In conclusion, the probe-based cdLAMP technique emerges as a user-friendly tool for detecting foodborne pathogens, providing a powerful platform for food safety testing.