Biosensors and Bioelectronics: X最新文献

Despite major advances in biosensing, quick, dependable, and effective on-site detection of bacterial infections remains a serious issue, owing to a lack of acceptable or appropriate diagnostic platforms. To address this gap, we presented a new colorimetric gold NanoZyme aptasensor for rapid sensing of Aeromonas veronii, an infectious bacterial disease in fish. The A. veronii-specific aptamer (AVS01) was developed through Cell-SELEX. The sensing mechanism involves inhibition of AuNPs induced peroxidase-mimic catalytic activity through surface adsorption by AVS01 which in the presence of the A. veronii desorb from the AuNPs allowing recovery of the catalytic activity leading to colorimetric response, whereas the sensor is insesnsitive to other nontarget bacterial cells. This method is very specific and sensitive, allowing for the quick and visible sensing of A. veronii with a detection limit of 1281 CFU mL⁻¹ within 15 min. The method has great potential for rapid diagnosis of bacterial infection in fish caused by A. veronii.

Sensors utilizing magneto-optical surface plasmon resonance are gaining increasing scientific and practical attention to detect atmospheric gases and humidity. The magneto-optic surface plasmon resonance wavelength is defined by the plasmonic structure's geometry and structure, making it immune to electromagnetic interference outside its resonance frequency range. The present study investigates their application for the detection of atmospheric gases including humidity. In contrast to conventional sensors, magneto-optic sensors exhibited excellent performance in terms of sensitivity (10 times greater), higher quality factor (up to 76 times higher) and design simplicity in terms of layer thickness optimization, integration, and robustness. These results suggest significant potential for utilization of magneto-optic sensors across multiple industries.

The recent pandemic improved awareness amongst the public of the need for rapid blood tests for community and home settings. In this work, we evaluated the performance of a digital, lipid panel test in microfluidic assay format which can be read using a smartphone camera. The PocDoc Lipid test is embedded within a cardiovascular screening application that utilizes the QRISK3 risk prediction algorithm to determine an individual's risk of having a cardiovascular event in the next 10 years and their healthy heart age. The test can be used to screen for individuals at risk of hyperlipidemia (e.g. high total cholesterol or triglycerides) and for individuals at high risk of cardiovascular disease at home or in community or surgery settings. The device was evaluated in a performance evaluation study, using 125 whole blood samples, following CLSI guidelines. Performance evaluation of the PocDoc device demonstrated accuracy that meets international NCEP guidelines and that is on par with other point-of-care tests. Sensitivity and specificity analysis supports the use of PocDoc to identify patients with hyperlipidemia or at high risk of cardiovascular disease. Bland-Altman analysis suggests that this point-of-care device can be used as an alternative to venous blood collection. This single-step model for cardiovascular disease risk measurement which can be done at home or in community settings may improve cardiovascular disease prevention.

The next generation of wearable biosensors comes with the latest advancements in biosensor technology. Soft and stretchable electrode materials like hydrogels with the similar functionalities of human tissue including stretchability, self-healability, and responsiveness to different stimuli have emerged as the most versatile materials in wearable electronics. The incorporation of conductive nanofillers is found to enhance the sensitivity of the electrochemical biosensors significantly. Microfluidic technology has reduced the volume of samples and reagents required for the analysis, allowing continuous biomedical monitoring from a drop of biofluid. In this paper, the most advanced progress in electrochemical wearable platforms that can noninvasively and continuously monitor the biochemical markers in body fluids for the diagnosis and health management is reviewed. Innovation in microelectronics, modification, fabrication technologies, and detection methods are the main focus of the discussion. In particular, hydrogel-based sensors and microfluidic systems as the latest technology trends in wearable detection are discussed in detail. Integration of miniaturized electrochemical wearable biosensors with wireless technology as a great promise for real-time healthcare monitoring and point-of-care (POC) diagnostics is also summarized. Finally, we outline the most advanced wearable biosensors with optimized material and design as well as key challenges that need to be addressed to improve sensing performance (accuracy, sensitivity, selectivity, stability), portability (miniaturized size and light weight), and flexibility of the wearable biosensors.

The present study involved the fabrication and testing of a Microchip electrophoresis (MCE) device for pulse amperometry based detection of pesticides from their mixture. We were able to separate and then quantify three distinct types of insecticides, namely Chlorpyrifos, Imidacloprid, and Fipronil using on chip MCE followed by pulsed amperometric detection. All these results were obtained with an inhouse developed potentiostat cum controller unit with a detection time of only 15 min, employing a minimal sample size of 2 μL without any preconcentration or extraction procedure. The limit of detection (LOD) was calculated as 42.69 μM, 62.61 μM, and 71.14 μM or 14.96, 16.0 and 31.09 ppm, respectively for Chlorpyrifos, Imidacloprid, and Fipronil and their respective migration times as 536 ± 6.3 s, 484 ± 1.7 s, and 604 ± 3.5 s (n = 14). The sensitivity of detection was determined as 0.03 nA/μM for Chlorpyrifos, 0.0265 nA/μM for Imidacloprid, and 0.035 nA/μM for Fipronil. In addition, the efficacy of the produced microchip was confirmed by analysing soil extract spiked with known pesticides concentrations while the recovery percentage, representing a ratio of calculated concentration to spiked concentration multiplied by hundred was found as 84.3% (±9.4%) (n = 9). Thus, integrating microchip technology with the developed analytical instruments presents significant promise for practical field applications and the analysis of diverse analytes by way of creating a library where the migration coefficient and peak detection current are needed for any analyte which can be made cationic or anionic using a suitable buffer.

Over the last decade, a significant paradigm shift has been observed towards leveraging less invasive biological fluids—such as skin interstitial fluid (ISF), sweat, tears, and saliva—for health monitoring. This evolution seeks to transcend traditional, invasive blood-based methods, offering a more accessible approach to health monitoring for non-specialized personnel. Skin ISF, with its profound resemblance to blood, emerges as a pivotal medium for the real-time, minimally invasive tracking of a broad spectrum of biomarkers, thus becoming an invaluable asset for correlating with blood-based data. Our exploration delves deeply into the development of wearable molecular biosensors, spotlighting dermal sensors for their pivotal roles across both clinical and everyday health monitoring scenarios and underscoring their contributions to the holistic One Health initiative. In bringing forward the myriad challenges that permeate this field, we also project future directions, notably the potential of skin ISF as a promising candidate for continuous health tracking.

Moreover, this paper aims to catalyse further exploration and innovation by presenting a curated selection of seminal technological advancements. Amidst the saturated landscape of analytical literature on translational challenges, our approach distinctly seeks to highlight recent developments. In attracting a wider spectrum of research groups to this versatile domain, we endeavour to broaden the collective understanding of its trajectory and potential, mapping the evolution of wearable biosensor technology. This strategy not only illuminates the transformative impact of wearable biosensors in reshaping health diagnostics and personalized medicine but also fosters increased participation and progress within the field. Distinct from recent manuscripts in this domain, our review serves as a distillation of key concepts, elucidating pivotal papers that mark the latest advancements in wearable sensors. Through presenting a curated collection of landmark studies and offering our perspectives on the challenges and forward paths, this paper seeks to guide new entrants in the area. We delineate a division between wearable epidermal and subdermal sensors—focusing on the latter as the future frontier—thereby establishing a unique discourse within the ongoing narrative on wearable sensing technologies.

Extracellular histone proteins in the blood indicate a heightened risk of morbidity after trauma or in major illnesses such as sepsis. We present the development of an aptasensor for histone detection with an extended gate field-effect transistor (EGFET) configuration, which benefits from low power consumption, rapid response, and compatibility with miniaturized gold electrodes. Histones have a high isoelectric point and charge density, which cause them to physically adsorb to non-specific elements of the sensor that have available electrostatic charges. To combat this, the sensing surface is formed with a thiol-modified, high-affinity and histone-specific RNA aptamer sequence and by co-immobilizing with poly(ethylene glycol) methyl ether thiol (PEG) as a blocking agent. Surface plasmon resonance (SPR) is used to analyze aptamer and PEG immobilization strategies, confirm histone binding, and calculate kinetic binding constants. Through comparison of different blocking agents and time-dependent preparation, the ideal equilibrium dissociation constant (K_D) is estimated to be below 200 pM, which is the upper range of extracellular histone concentrations in critically ill patients with high mortality. The EGFET sensitivity of the optimized aptasensor is 6.65 mV/decade concentration change for histone H4 with a physiologically relevant 5 pM limit of detection. Selectivity tests with 100 nM bovine serum albumin (BSA) demonstrate a signal response that is 13-fold smaller than for histones. This EGFET aptasensor platform is suitable for future point-of-care monitoring of histone levels in critically ill patients, thus permitting the early detection of increased risk and the need for more aggressive interventional measures to prevent mortality.

This article has tried to provide an overview of the most sophisticated microfluidic biosensors for identifying nucleic acids and proteins at the site of treatment. Microfluidics, which also automates sample preparation and reduces processing time and reagent consumption, enables the analysis of small sample quantities. Microfluidics and biosensor technologies collaborate to provide diagnostics at the point of care with high throughput analysis, portability, and disposability. The high sensitivity and selectivity requirements, false response errors, and integration with other essential modules are some of the challenges posed by this merger. The broad categories of protein-based and DNA-based biosensor technology are covered in this review. Also, recent advancements in coupling the biosensors to microfluidics, the main challenges and potential solutions in deploying microfluidic biosensors for point-of-care diagnostics, and the most recent developments in these areas have been discussed.

PD1/PD-L1 checkpoint inhibitors are at the forefront of cancer immunotherapies. However, the overall response rate remains only 10–30%. Even among initial responders, drug resistance often occurs, which can lead to prolonged use of a futile therapy in the race with the fatal disease. It would be ideal to closely monitor key indicators of patients’ immune responsiveness, such as circulating PD-L1 levels. Traditional PD-L1 detection methods, such as ELISA, are limited in sensitivity and rely on core lab facilities, preventing their use for the regular monitoring. Electrochemical sensors exist as an attractive candidate for point-of-care tool, yet, streamlining multiple processes in a single platform remains a challenge. To overcome this challenge, this work integrated electrochemical sensor arrays into a digital microfluidic device to combine their distinct merits, so that soluble PD-L1 (sPD-L1) molecules can be rapidly detected in a programmed and automated manner. This new platform featured microscale electrochemical sensor arrays modified with electrically conductive 3D matrix, and can detect as low as 1 pg/mL sPD-L1 with high specificity. The sensors also have desired repeatability and can obtain reproducible results on different days. To demonstrate the functionality of the device to process more complex biofluids, we used the device to detect sPD-L1 molecules secreted by human breast cancer cell line in culture media directly and observed 2X increase in signal compared with control experiment. This novel platform holds promise for the close monitoring of sPD-L1 level in human physiological fluids to evaluate the efficacy of PD-1/PD-L1 immunotherapy.

Human adenosine deaminase acting on RNA1 (ADAR1) is an adenosine-to-inosine (A-to-I) RNA-editing enzyme involved in various types of cancer progression. ADAR1 has emerged as a novel prognostic biomarker for cancer. This study describes the application of a newly identified 70-nt DNA aptamer (Apt38483) against ADAR1 to develop a portable and simple electrochemical biosensor platform for the rapid and sensitive detection of ADAR1 in cell lysates. We selected an ADAR1-specific DNA aptamer from a randomized 70-nt single-stranded DNA library using a competitive in vitro selection method. ADAR1 in the cell lysate was sandwiched onto a bare carbon working electrode of an electro-chemically printed chip between the ADAR1 antibody and gold nanoparticles (40 nm) conjugated with Apt38483, followed by electrochemical analysis using differential pulse voltammetry (DPV) for sensor demonstration. A highly sensitive change in current was observed for as little as 0.53 nM ADAR1 in human embryonic kidney cell lysate. Thus, the merging of a novel DNA aptamer probe for ADAR1 with an electrochemical transduction method enabled the development of a simple, low-cost, and rapid method for the direct measurement of ADAR1 in cell lysates and indicated great potential for the development of an ADAR1 analysis platform, which would be useful in cancer prognosis.