Dual-channel Biosensor Research Articles

A Dual-Channel Biosensor Enables Concurrent Detection of Pathogens and Antibiotic Resistance

Diarrhoeagenic infections, commonly treated with β-lactam antibiotics, contribute to antibiotic resistance - a pressing public health concern. Rapid monitoring of pathogen antibiotic resistance is vital to combat antimicrobial spread. Current bacterial diagnosis methods identify pathogens or determine antibiotic resistance separately, necessitating multiple assays. There is an urgent need for tools that simultaneously identify infectious agents and their antibiotic resistance at the point of care (POC). We developed an integrated electrochemical chip-based biosensor for detecting enteropathogenic E. coli. Leveraging an antibody against the virulence marker EspB, the dual-channel chip facilitated electrochemical impedance spectroscopy-based detection of EspB antigen (sensitivity of 10 ng/mL) and EspB-expressing bacteria. For β-lactam resistance profiling, a second channel enabled differential-pulse voltammetric measurement of hydrolyzed nitrocefin, a β-lactam analogue, demonstrating sensitive detection of the antibiotic resistance marker, β-lactamase at concentrations as low as 1 ng/mL. The integrated electrochemical biosensor successfully achieved simultaneous, rapid detection of double positive EspB- and β-lactamase-expressing bacteria, promoting advancements in POC clinical diagnosis.

Upconversion luminescence resonance energy transfer (LRET)-based dual-channel biosensor for rapid detection of coronavirus

Researchers recently have been working on a sensitive, accurate, and easily accessible way to detect coronaviruses. Traditional polymerase chain reaction detection technology has high sensitivity and specificity, but there are some problems, such as a complicated detection process, false negatives caused by gene mutation of coronavirus, and easy infection of operators. Antigen detection, which does not require gene amplification and other preprocessing, can be operated by non-medical staff for rapid detection. However, its detection sensitivity requires high reliability and further improvement. Accordingly, a biosensor based on luminescent resonance energy transfer (LRET) from upconversion nanoparticles (UCNPs) to gold nanoparticles (AuNPs) and antigen detection has been developed for rapid and sensitive detection of N protein of SARS-CoV-2. By adjusting the reaction conditions, LRET can be realized by making the spectral overlap between the luminescence of UCNPs and the absorption band of AuNPs, which can effectively avoid the generation of biological background light and the interference of other signals in the test process. In addition, the thiol-ene click reaction was used to link Thiol-PEG-COOH to UCNPs to improve its biocompatibility. The antigen recognition of the coronavirus based on the as-proposed detection method can be further realized on the test paper. A linear response is obtained ranging from 10 ng mL−1 to 1280 ng mL−1, and the detection limit is around 0.80 ng mL−1 with a detection time of around 10 minutes, which has a wide range of potential future. This fast and sensitive biosensor for coronavirus detection can be further reflected in the test paper and is promising for practical applications.

Point-of-Care Detection of HER2 and CA 15-3 in Breast Cancer Patients: Dual-Channel Biosensor Implementation

Breast cancer remains a considerable health challenge, affecting numerous individuals annually. This research introduces an innovative method for detecting breast cancer utilizing dual-channel test strips capable of simultaneously assessing two key biomarkers—HER2 and CA 15-3. The test strip utilized in this study is not only cost-effective but also entirely non-invasive. The reusable device employs a printed circuit board with metal-oxide-semiconductor field-effect transistor amplification and Arduino-based control to convert voltage signals from test strips into digital readings efficiently. The device utilizes double-pulse measurement instead of direct current, effectively mitigating the screening effect. The detection limit for both biomarkers is exceptionally low at 10−15 g ml−1, surpassing commercial enzyme-linked immunoassay kits by four orders of magnitude. The sensor demonstrates remarkable sensitivity, with 78/dec for HER2 and 56/dec for CA 15-3. Human sample tests were conducted to validate the efficacy of the dual-channel strip, successfully distinguishing between healthy and cancerous groups. The results reveal significant p-values for both HER2 and CA 15-3 tests, underscoring the significance of this research. Note that this is a rapid testing process, completed in less than 2 s. These findings offer a promising avenue for swift and accurate breast cancer detection, furnishing crucial insights for early diagnosis and subsequent treatment.

Electrochemical and colorimetric dual-channel biosensor based on B and N co-doped carbon nanotubes

Rational design of efficient metal-free doped carbon nanotubes to construct dual-channel sensing platforms remains a challenge. In this study, B and N co-doped carbon nanotubes (BNCNTs) were designed and produced by one-step pyrolysis of P123, boric acid and urea, in which P123 could act as a structural guide to promote the generation of nanotubes. The synergistic effect of B and N doping can modulate the electronic structure of the skeleton, where B can reduce the valence band and the N could excite the conduction band. This can promote electron transport and create more active sites. As a result of the hollow tubes and the synergistic effect of B and N doping, the BNCNTs are an excellent electrocatalyst which could be candidates for electrode modification materials. In addition, the BNCNTs also exhibit excellent peroxidase activity. Therefore, BNCNTs were employed conduct an electrochemical and colorimetric dual channel sensing platform for the detection of uric acid in the range of 2–400 μM and 5–200 μM, with the detection limits of 0.078 μM and 4.52 μM, respectively. This work presents a method for the preparation of metal-free doped carbon nanotubes as multifunctional catalysts for applications in nanozymes, sensing, clinical diagnostics, and other fields.

Dual-channel biosensor for simultaneous detection of S. typhimurium and L. monocytogenes using nanotags of gold nanoparticles loaded metal-organic frameworks

Simultaneous detection of multiple foodborne pathogens is of great importance for ensuring food safety. Herein, we present a sensitive dual-channel electrochemical biosensor based on copper metal organic frameworks (CuMOF) and lead metal organic framework (PbMOF) for simultaneous detection of Salmonella typhimurium (S. typhimurium) and Listeria monocytogenes (L. monocytogenes). The MOF-based nanotags were prepared by functionalizing gold nanoparticles loaded CuMOF (Au@CuMOF) and PbMOF (Au@PbMOF) with signal DNA sequences 1 (sDNA1) and sDNA2, respectively. By selecting invA of S. typhimurium and inlA gene of L. monocytogenes as targe sequences, a sandwich-typed dual-channel biosensor was developed on glassy carbon electrodes (GCE) through hybridization reactions. The sensitive detection of S. typhimurium and L. monocytogenes was achieved by the direct differential pulse voltametric (DPV) signals of Cu2+ and Pb2+. Under optimal conditions, channel 1 of the biosensor showed linear range for invA gene of S. typhimurium in 1 × 10−14−1 × 10−8 M with low detection limit (LOD) of 3.42 × 10−16 M (S/N = 3), and channel 2 of the biosensor showed linear range for inlA gene of L. monocytogenes in 1 × 10−13−1 × 10−8 M with LOD of 6.11 × 10−15 M (S/N = 3). The dual-channel biosensor showed good selectivity which were used to detect S. typhimurium with linear range of 5−1.0 × 104 CFU mL−1 (LOD of 2.33 CFU mL−1), and L. monocytogenes with linear range of 10 − 1.0 × 104 CFU mL−1 (LOD of 6.61 CFU mL−1).

Artificial neural network-facilitated V2C MNs-based colorimetric/fluorescence dual-channel biosensor for highly sensitive detection of AFB1 in peanut

In this work, V2C Mxene nano-enzyme materials (V2C MNs) with excellent peroxidase-like activity and fluorescence quenching performance were prepared, and it was modified using 6-carboxyfluorescein-labelled aptamers (ssDNA-FAM) to construct a novel dual-mode sensor V2C@ssDNA-FAM, with detection limits of 0.0477 ng mL−1 and 0.2789 ng mL−1 of fluorescence (linear range of 0.1–550 ng mL−1) and colorimetric (linear range of 1–1000 ng mL−1) modes, respectively. Meanwhile, an ANN intelligent detection platform has been constructed, which could automatically track and analyze the fluorescence and colorimetric signal of the detection system through machine learning and immediately obtain the AFB1 concentration, and the detection limits of the fluorescence (linear range of 0.1–500 ng mL−1) and colorimetric (linear range of 1–800 ng mL−1) channels of it were 0.0905 ng mL−1 and 0.6845 ng mL−1, respectively. The recovery rates of fluorescence, colorimetric sensing detection and ANN-assisted fluorescence and colorimetric sensing detection of real samples ranged from 95.40% to 101.76%. The method constructed in this work was superior to most existing literature reports and had great potential for application in the field of food quality testing.

Killing two birds with one stone: Construction of a rare earth hybrid dual-channel fluorescent biosensor with intelligent broadcasting function and visualized synchronous assessment of multi-objectives

Contamination of pathogenic bacteria and abuse of antibiotics have become important factors restricting the healthy and rapid development of animal husbandry. Simultaneous quantitative detection of pathogenic bacteria and antibiotics is not only the need of animal husbandry development, but also a challenge in the development of sensor analysis technology. In this study, a dual-channel fluorescent biosensor based on tubular halloysite (THT) loaded with carbon dots and lanthanide bimetal organic frameworks was prepared (THT@CDs-MOF), which contained blue emitters (peak emission at 450 nm under 365 nm excitation) and red emitters (peak emission at 616 nm under 254 nm excitation). The obtained dual-channel biosensor can realize quick visual intelligent assessment of 2,6-pyridinedicarboxylic acid (DPA) through energy transfer under 254 nm excitation and tetracycline (TC) through antenna effect and internal filtering effect (IFE) under 365 nm excitation. This biosensor can detect DPA with a concentration of 0–72 μM (LOD was 6.07 nM) and TC with a concentration of 0–19 μM (LOD was 11.31 nM). By fixing the biosensor on agarose, a biosensor with rapid visualization for simultaneous detection of DPA and TC was obtained. Importantly, a color recognition speech broadcasting system based on 51 single-chip microcomputer for the real-time semi-quantitative identification of DPA and TC was also developed, which promoted the application of artificial intelligence in the field of small molecules analysis.

A Flexible Dual-Analyte Electrochemical Biosensor for Salivary Glucose and Lactate Detection.

Electrochemical biosensors have been widely applied in the development of metabolite detection systems for disease management. However, conventional intravenous and fingertip blood tests are invasive and cannot track dynamic trends of multiple metabolites. Among various body fluids, saliva can be easily accessed and is regarded as a promising candidate for non-invasive metabolite detection. Recent works on the development of electrochemical biosensors for monitoring salivary metabolites have demonstrated high sensitivity and wide linear range. However, most of this research has been focused on salivary detection of a single metabolite. Here, we present a dual-channel electrochemical biosensor for simultaneous detection of lactate and glucose in saliva based on a flexible screen-printed electrode with two working electrodes. The sensitivities of glucose and lactate channels were 18.7 μA/(mM·cm2) and 21.8 μA/(mM·cm2), respectively. The dual-channel biosensor exhibited wide linear ranges of 0–1500 μM for the glucose channel and 0–2000 μM for the lactate channel and the cross-talk between the two detection channels was negligible, which made it adequately suitable for sensing low-level salivary metabolites. Such attractive characteristics demonstrate the potential of this dual-analyte biosensor in the development of wearable devices for monitoring disease progression and fitness.

Simple Design Concept for Dual-Channel Detection of Ochratoxin A Based on Bifunctional Metal-Organic Framework.

A simple fluorescence and electrochemical dual-channel biosensor based on bifunctional Zr(IV)-based metal-organic framework (Zr-MOF) was proposed to detect Ochratoxin A (OTA). The bifunctional Zr-MOF, with photoluminescence properties and enormous electroactive ligands, was exploited to load OTA-specific aptamers for designing signal probes, greatly simplifying the probe-fabrication process and improving sensing reliability. Upon specific recognition of aptamer toward OTA, the anchored probe was released from the sensing interface into the reaction solution. In this circumstance, the increased amount of the signal probe in reaction solution led to an enhanced fluorescence response, while the decreased amount of the signal probe on the sensing interface resulted in a diminished electrochemical response. According to the dual-channel signal change with increasing OTA concentration, the visual fluorescence strategy was established for intuitive OTA detection, and meanwhile, sensitive electrochemical assay with a detection limit of 0.024 pg/mL was also achieved with the help of one-step electrodeposition as a sensing platform. Moreover, the proposed dual-channel assay has been successfully applied to determine OTA levels in corn samples with rapid response, superior accuracy, and high anti-interference capability, providing a promising method for food safety monitoring.

L-Tryptophan assisted construction of fluorescent and colorimetric dual-channel biosensor for detection of live Escherichia coli

Detection of hygiene indicator Escherichia coli (E. coli) is usually employed for assessing the hygiene and safety of water and food supply. Herein, an L-tryptophan (L-Trp)-based fluorescent and colorimetric dual-channel sensing system was developed for detection of live E. coli. The fluorescent channel is based on the stereo-specifically degradation of L-Trp by tryptophanase excreted by E. coli, while L-Trp can be served as a fluorescent indicator. The colorimetric channel is based on the chromogenic reaction between the degradation product indole and 4-dimethylaminobenzaldehyde. Importantly, the dual-channel sensing system can distinguish live E. coli from dead bacteria. Also, the system demonstrates excellent selectivity toward E. coli due to the highest specific activity of tryptophanase in E. coli. In addition, a smartphone-based potable device was designed and used to capture the images, and ImageJ software was used for the analysis of the color thresholds and gray values of images. The feasibility of the sensing system was verified by successful detection of E. coli in river water and milk samples with recoveries in the range of 90.2% to 108%. The sensing system provides an alternative platform for convenient and selective detection of E. coli in water and food products.

Dual-channel biosensor for Hg2+ sensing in food using Au@Ag/graphene-upconversion nanohybrids as metal-enhanced fluorescence and SERS indicators

Here, we proposed a novel dual-channel biosensor for rapid and sensitive detection of Hg2+. Compared with the previous biosensors, the Au@Ag/graphene-upconversion (Au@Ag-GU) was prepared via a facile method and acted as a versatile signal indicator that can simultaneously readout surface-enhanced Raman spectroscopy (SERS) and fluorescence signals for Hg2+detection. In this strategy, the core shell magnetite colloid nanocrystal clusters-polymethacrylic acid magnetic beads (MCNCs/PMAA MBs) were synthesized and conjugated with aptamer to specific capture the Hg2+. The dual-channel biosensor was thus fabricated by immobilizing the Au@Ag-GU onto the surface of MBs through the complementary pairing of aptamer and complementary DNA (cDNA). Upon Hg2+ incubation, Hg2+ preferably bound to the MBs-aptamer, resulting in the subsequent release of preloaded cDNA-Au@Ag-GU into supernatants. Under magnetic attraction, the MBs-aptamer was accumulated immediately, resulting in the concentration of Hg2+ become homodromous proportional to the dual channel intensity of the supernatants. Under the optimized conditions, the dual channel biosensor achieved excellent performances for Hg2+ with limits of detection (LOD) of 0.33 and 1 ppb, respectively. Furthermore, the feasibility of the biosensor to qualify Hg2+was also established in spiked tap water and milk samples. This strategy may provide a bridge between a highly sensitive fluorescence assay and a rapid SERS assay, it can broaden the applicability of Hg2+ detection, which can be easy to detect Hg2+ in real samples by coupling with SERS or fluorescence assay.

Dual-channel sensing strategy based on gold nanoparticles cooperating with carbon dots and hairpin structure for assaying RNA and DNA

By employing the attractive performance of fluorescent carbon dots and the assistant of hairpin structure, an innovative dual-channel biosensor on the basis of gold nanoparticles (AuNPs) for detecting multiple nucleotide sequences has been successfully proposed. In brief, the fluorescence of carbon dots (CDs) was quenched in the absence of the targets, and the hairpin structure was hybridized with the AuNPs-DNA and resulted in recovering the fluorescence. Instead, the presence of breast cancer (BRCA1) RNA/DNA could specifically bind with its contrary sequence to release the CDs from AuNPs, hence leading to the fluorescence recovery as a positive signal. Again, the hairpin structure can be released in the presence of thymidine kinase (TK1) RNA/DNA, thus induced a fluorescence quenching accordingly. Subsequently, the prepared sensing model was applied to detect BRCA1 RNA/DNA respectively accompanied with a linear range of 4–120nM as well as a detection limit of 1.5nM and 2.1nM, and 10–120nM as well as a detection limit of 3.6nM and 4.5nM for TK1 RNA/DNA respectively. More importantly, this sensing model could assay any possible gene sequence or aptamer-substrate complexes by appropriately programming.

Functionalized periodic Au@MOFs nanoparticle arrays as biosensors for dual-channel detection through the complementary effect of SPR and diffraction peaks

A facile and low-cost method to prepare periodic Au@metal–organic framework (MOF) (MIL-100(Fe)) nanoparticle arrays was developed. The arrays were fabricated in situ using monolayer colloidal crystals as templates, followed by Au deposition on substrates, and annealing. MIL-100(Fe) coatings were applied on the nanospheres using a simple solvent thermal process. The prepared periodic Au@MIL-100(Fe) nanoparticle (NP) arrays were characterized by two peaks in the visible spectra. The first peak represented the surface plasmon resonance (SPR) of the Au nanospheres, and the other peak, or the diffraction peak, originated from the periodic structure in the NP array. After modification with 3-aminophenylboronic acid hemisulfate (PBA), the Au@MIL-100(Fe) NP arrays exhibited sensitive responses to different glucose concentrations with good selectivity. These responses could be due to the strong interaction between PBA and glucose molecules. The diffraction peak was sensitive at low glucose concentrations (less than 12 mM), whereas the SPR peak rapidly responded at high concentrations. The peaks thus demonstrated satisfactory complementary sensitivity for glucose detection in different concentration regions. These results can be used to develop a dual-channel biosensor. We also created a standard diagram, which can be used to efficiently monitor blood glucose levels. The proposed strategy can be extended to develop different dual-channel sensors using Au@MIL-100(Fe) NP arrays functionalized with different recognition agents.

Misalign-dependent double plasmon modes “switch” of gold triangular nanoplate dimers

The optical properties of the edge-to-edge gold triangular nanoplate dimers have been studied in theory by discrete dipole approximation method. Two clearly separated plasmon modes (low-energy and high-energy modes) are observed. Each of the double plasmon modes could be selectively turned on or off by modulating the misalign value of the dimer. When the misalign is <60 nm, the low-energy mode plays the dominant role in the spectra. In this case, the electric field intensities at the tips along the polarization direction fade down, whereas the intense electric field in the gap gets more concentrative, as the misalign increases. However, as the misalign is increased to 100 nm, the high-energy mode dominates the spectrum. And the intense electric fields concentrated around the outer tips become stronger as the misalign increases. The “switch” process is also accompanied by the inversion of the field vectors in the gap. In addition, the wavelength separation and positions of the double plasmon modes could be tuned flexibly by adjusting the gap value and the thickness of the dimer, respectively. These findings are promising for the nanophotonic switch, nanomotor, molecular ruler, surface enhanced fluorescence, surface enhanced Raman scattering, dual channel biosensor, and molecular imaging applications.

Rapid and Highly Sensitive Method for Influenza A (H1N1) Virus Detection

In this study, we applied the developed paired surface plasma waves biosensor (PSPWB) in a dual-channel biosensor for rapid and sensitive detection of swine-origin influenza A (H1N1) virus (S-OIV). In conjunction with the amplitude ratio of the signal and the reference channel, the stability of the PSPWB system is significantly improved experimentally. The theoretical limit of detection (LOD) of the dual-channel PSPWB for S-OIV is 30 PFU/mL (PFU, plaque-forming unit), which was calculated from the fitting curve of the surface plasmon resonance signal with a S-OIV clinical isolate concentration in phosphate-buffered saline (PBS) over a range of 18-1.8 × 10(6) PFU/mL. The LOD is 2 orders of magnitude more sensitive than the commercial rapid influenza diagnostic test at worst and an order of magnitude less sensitive than real-time quantitative polymerase chain reaction (PCR) whose LOD for S-OIV in PBS was determined to be 3.5 PFU/mL in this experiment. Furthermore, under in vivo conditions, this experiment demonstrates that the assay successfully measured S-OIV at a concentration of 1.8 × 10(2) PFU/mL in mimic solution, which contained PBS-diluted normal human nasal mucosa. Most importantly, the assay time took less than 20 min. From the results, the dual-channel PSPWB potentially offers great opportunity in developing an alternative PCR-free diagnostic method for rapid, sensitive, and accurate detection of viral pathogens with epidemiological relevance in clinical samples by using an appropriate pathogen-specific antibody.

A polymeric dual-channel amperometric biosensor chip capable of symmetrically splitting sample bands for parallel micro flow injection determination of glucose and lactate

This paper presents a chip-based dual-channel micro flow injection biosensor system for parallel determination of two components that potentially interference with each other. With glucose and lactate being the model analytes, a hybrid polydimethylsiloxane (PDMS)–polycarbonate (PC) microfluidic chip with a Y-shaped main-to-branch channel network was designed. Glucose oxidase (GOD) and lactate oxidase (LOD) biosensors of amperometric type were separately prepared inside each of the two branch channels. A sample band injected into the main channel was split into two daughter bands at the bifurcated point of the Y-shaped channel. The daughter bands were delivered into branches where the two analytes in the daughter bands were independently detected by the GOD and LOD sensors, preventing the potential chemical crosstalk between the two sensors. Factors influencing the symmetry of splitting a sample band, in turn, the sensitivity and reproducibility of the system, were discussed. Symmetric splitting was realized by using back pressure regulators (BPR). Under optimized conditions, detection limits of 78 μmol L−1 for glucose and 127 μmol L−1 for lactate were observed with a sample volume of 20 nL and a sample throughput rate of 40 h−1. RSDs of 0.8–0.9% for peak heights were observed for 11 runs of a standard solution containing glucose and lactate both at 2 mmol L−1. The designed dual-channel biosensor chip was applied to the simultaneous determination of glucose and lactate in human serum samples.