Biosensors and Bioelectronics: X最新文献

Continuous glucose monitoring (CGM) using implantable glucose sensors is a critical tool in the management of diabetes. Unfortunately, current commercial glucose sensors have limited performance and lifespans in vivo, considered to be due to sensor-induced tissue reactions (inflammation, fibrosis, and vessel regression). Previously, our laboratory utilized monocyte/macrophage (Mo/MQ) deficient and depleted mice to establish a causal relationship between Mo/MQ accumulation and inflammation in glucose sensor performance in vivo. Using C–C chemokine ligand-2 (CCL2) and C–C chemokine receptor-2 (CCR2) knockout mice, we next established that deletion of this Mo/MQ chemokine family, suppressed inflammation at the sensor-tissue interface in these mice, while improving sensor performance over a 4-week post-sensor implantation, compared to normal mice. These studies underscore the importance of the CCL2 family of chemokines and receptors in Mo/MQ recruitment/activation, and sensor performance in vivo. In the present study, we systemically administered Bindarit, a CCL2 synthesis inhibitor, to assess the role of CCL2 chemokines, Mo/MQ recruitment and inflammation at sensor implantation sites, on CGM performance in vivo. These studies demonstrate that systemic administration of Bindarit substantially reduced sensor-induced inflammation, particularly MQ recruitment, preventing sensor biofouling in our CGM mouse model. These results not only confirm the major role monocytes/macrophages play, but directly demonstrate that CCL2 drives Mo/MQ recruitment and biofouling of glucose sensors in vivo. These findings support future studies incorporating Mo/MQ migration/chemotaxis inhibitors, like CCL2, on sensor coatings to improve glucose sensor accuracy and lifespan in vivo.

Fluorescence-based probes have been the key interest of researchers working at the intersection of chemistry and biology. Such probes are crucial for strengthening our understanding about biochemical processes, drug delivery, and fluorescence-guided surgery. A challenge in this regard is optimizing the probe's aqueous solubility while maintaining its lipophilicity to allow cell membrane permeation. This review summarizes the recent progress in water-soluble fluorescence-based probes for different types of biomolecules including carbohydrates, proteins, enzymes, amino acids, neurotransmitters and biologically relevant reactive species. A comprehensive overview of the crucial parameters for such probes' design, potential sensing mechanism for specific analytes, and experimental conditions for sensing has been provided. Incorporation of hydrophilic functional groups, ionic charge(s), absorption-emission characteristics and pH-stability in biological window are pivotal to develop optimized probes with high sensitivity for target biomarkers. We further underline the limitations of the probes that hinder their translation to clinical research and also indicate major research gap in optimizing any single probe for a certain biomarker.

Solid-contact (SC) ion-selective electrodes (ISEs) are often employed in wearables for electrolytes detection owing to their simplicity and ease of miniaturization. However, to mitigate their inherently unstable open circuit potential signal, ISEs require long hours of conditioning and frequent calibration prior to and during operation, limiting their practicality in wearable applications. Inspired by strategies to address water crossover and flooding in polyelectrolyte fuel cells, we demonstrated a SCISE with minimal conditioning time and long-term stability by modulating the rate-limiting step between mass transfer of water and hydrated ions and redox kinetics in the conducting polymer (CP). Our strategy comprised a wearable ISE with a superhydrophobic CP, PEDOT:TFPB, which reduced water and ion fluxes within the ISE, resulting in a stable and less-swollen CP and diminished water layer formation while maintaining CP's high capacitance. Our PEDOT:TFPB based ISEs functioned after a short conditioning time of 30 min and exhibited extended stability with a reduced signal deviation of only 0.16 % per hour (0.02 mV h⁻¹) during 48 h of continuous measurement. Through systematic studies, we showed that ISE performance could be further tuned by tailoring the thickness of the ion-selective membrane as well as the hydrophobicity and polymerization charges of the CP. Without the need for recurrent calibration, our ISEs sustain high accuracy and prolonged stability upon integration into a wearable format for on-body perspiration analysis. Our strategy allows wearable ion-selective sensors with minimal maintenance at the user-end for long-term continuous monitoring, unveiling their potential in sports, healthcare, and diagnosis fields.

Supercapacitors are an interesting energy storage technology to be studied. This research uses mesoporous BaFe₁₂O₁₉ particles and synthesized Polyvinylidene fluoride (PVDF) polymers as materials to obtain high performance supercapacitors. Composites were synthesized by facile one-step method using BaFe₁₂O₁₉ which was prepared through co-precipitation chemical method with a calcination process at 200 °C along with PVDF with variations in sample composition of BaFe₁₂O₁₉, BaFe₁₂O₁₉ 20%, BaFe₁₂O₁₉ 30%, BaFe₁₂O₁₉ 40%, and BaFe₁₂O₁₉ 60%. And finally the fabrication of supercapacitor electrodes is carried out. The result of the synthesized material is distributed grains with the average particle size of each sample ranging from 180 to 185 nm. Then it has the highest peak in crystals with a miller index (114). Furthermore, it has the main functional group, Ba–O with a wave number of 1632 cm⁻¹. Furthermore, the best supercapacitor electrode is BaFe₁₂O₁₉/PVDF 60% which produces an area of 0.51 mVA where the greater the surface area, the higher the capacitance obtained. Then at BaFe₁₂O₁₉/PVDF 60% has the highest power density value at 12.36 Wh/kg and the highest power density value at 299.14 Wh/kg. It is expected that the results obtained can be a reference for further electrode material research.

Vanadium nitride-poly (0-methoxy aniline)- poly(3,4-ethylene dioxythiophene) (VN-POMA-PEDOT) hybrid was synthesized via ammonolysis and chemical oxidative polymerization technique using VN-POMA-PEDOT/GCE with electrocatalytic activity has two dimensional VN hierarchical porosity with POMA-PEDOT structure created VN-POMA-PEDOT modified GCE working electrode. Donor-acceptor behavior and double-layer growth enable enhanced electrochemical performance and catalytic activity of mebendazole (MBZ). This work investigated the electrochemical sensing conduct of a VN-POMA-PEDOT hybrid composite towards MBZ. The detection limit (DL) and quantification limit (QL) were determined to be 2.192 × 10⁻⁹ μM μA⁻¹ and 5.245 × 10⁻⁹ M μA⁻¹. Estimation of anti-interference ability, long-term stability, and reproducibility revealed that the prepared VN-POMA-PEDOT electrode is appropriate for the electrochemical sensing finding of MBZ in real analysis, such by way of anti-helminthic drug milk. The VN-POMA-PEDOT achieved 98.9% efficiency in the photocatalytic degradation of methylene blue (MB) within 50 min with degradation rate 8.3 × 10⁻³ min⁻¹. The suppleness of this method was confirmed by the hybrid morphology VN-POMA-PEDOT, which shows an enormously superior and enhanced photocatalytic presentation of MB.

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.