Biosensors and Bioelectronics: X最新文献

Cancer continues to be a significant global health issue with one in six deaths linked to the disease despite advancements in cancer detection and treatment. Recently, Helicobacter pylori (H. pylori) was identified as a risk factor for cancer development. This gram-negative bacterium is associated with gastric conditions, including stomach cancer. Although the exact transmission methods of this bacterium are still unclear, studies suggest that waterborne transmission is possible. This study focuses on the development of a colorimetric nanomaterial-based paper biosensor for specific H. pylori detection using H. pylori extracellular proteases as biomarkers. The biosensor utilizes a unique substrate labeled with magnetic nanobeads and bound to a gold sensing platform. The biosensor's limit of detection (LOD) of 100 CFU/mL, selectivity, stability, and ability to detect H. pylori in clinical specimens were evaluated, demonstrating promising results in terms of sensitivity and specificity. In comparison to traditional methods, this biosensor offers advantages in simplicity and ease of use, making it appropriate for on-site detection in both environmental and clinical settings.

Dengue fever, a mosquito-borne viral infection, poses a significant global health threat, and early diagnosis is crucial for effective disease management. The utilization of advanced materials in the design ensures an improved surface area, facilitating a heightened interaction between the sensor and the target. In this study, the incorporation of biomass-derived high-surface porous carbon-based materials not only contributed to the sensor's sensitivity but also ensured a cost-effective and scalable manufacturing process. The electrochemical nature of the biosensor added a layer of precision to the detection process and offered a reliable, rapid method for identifying the infection of the dengue virus. The enhanced sensitivity of the biosensor allowed the detection of even trace amounts of the NS1 protein, enabling early diagnosis in the initial stages of dengue infection. The system exhibited a high sensitivity with a wide linear range between 1 pg/mL and 100 μg/mL, and the extremely low detection limit of 0.665 pg/mL ranks this as one of the most efficient biosensors for the detection of dengue virus NS1 protein. Selectivity studies, coupled with computational insights, showcased the biosensor's prowess in distinguishing NS1 protein from potential interfering substances, laying the foundation for reliable diagnostics in complex biological matrices. Real sample analysis using human serum spiked with NS1 protein offers a tantalizing glimpse into the transformative potential of biosensors in real-world scenarios. This innovative biosensor holds great promise for addressing the pressing need for early detection of dengue virus infections.

HeLa cervical cancer cells are immortal with telomerase activity and metastatic characteristics similar to circulating tumor cells (CTCs). Here, we report aptamer-modified multilayered magnetic beads (Apt@MBs) that efficiently targeted and captured HeLa cells up to a low concentration of freshly prepared cell suspension (500 cells/mL). Apt@MBs were functionalized with fluorophore-conjugated AS1411-aptamer on an outer layer made up of molybdenum disulfide (MoS₂) to target nucleolin on the cell surface of captured HeLa cells. Moreover, this outer MoS₂ layer of MBs was nanoporous and could load anticancer drugs inside its porous cavities with the possibility of killing the captured and metastatic CTCs in vivo. An internal core layer of Apt@MBs consisting of Ag–Fe₃O₄ magnetic particles (MPs) was designed for magnetic manifestations and cell sorting with the possibility of screening CTCs (in the patient's blood samples) for early diagnosis of metastatic cancers. The Apt@MBs after cell capture gave rise to the heavier HeLa-MBs composites to get settled down under gravitational/inertial forces to the bottom of the tube quicker than the free cells (within 10 min). The gravitational settling of HeLa-MBs was further coupled with exposing a magnetic field to effectively capture and enrich the cells at the bottom of the tube (from 91 to 98 % cells). While the fluid containing dead, non-cancerous, or uncaptured cells in the supernatant layers were easily removed by pipetting. The HeLa-MBs after sorting out were resuspended into a fresh culture medium for further incubation or cellular analysis. Moreover, both cisplatin (CP) and epirubicin (EP) loaded Apt@MBs showed the killing of about 50 % of the captured cells. Therefore, we are confident that Apt@MBs can contribute to enumerating patients' blood samples for screening CTCs to timely and efficiently detect metastatic cancers along with the ability to effectively perform prognosis, and treatment of metastatic cancers.

Phosphorylated Tau proteins are promising biomarkers for the diagnosis and prognosis of Alzheimer's disease. This study presents a novel voltametric sensor using a vanadium MXene polydopamine (V_xPDA) redox active composite and a Tau-441-specific polyaniline molecularly imprinted polymer (PANI MIP) for the sensitive detection of Tau-441 in interstitial fluid (ISF) and plasma. The V_xPDA/PANI MIP sensor demonstrates a broad detection range of 5 fg/mL to 5 ng/mL (122 aM/L to 122 pM/L) in ISF without the use of redox mediators, with a lower limit of detection (LOD) of 2.3 fg/mL (60 aM/L). Furthermore, a handheld device utilizing this technology successfully detects Tau-441 in artificial serum with high sensitivity (5 fg/mL to 150 fg/mL (122 aM/L to 366 aM/L)) and specificity within a clinically relevant range. The rapid detection time (∼32 min) and low cost (∼£20/device) of this sensor highlight its potential for minimally invasive, early AD diagnosis in clinical settings. This advancement aims to facilitate a transition away from invasive cerebrospinal fluid (CSF)-based diagnostic techniques for AD.

Nanozyme cascade have garnered substantial interest in recent years due to their distinctive properties. However, the conventional stepwise cascade reaction undergoes tedious two-step operation process owing to the incompatibility of reaction conditions. Moreover, most of reported nanozymes exhibit favorable catalytic performance only in acidic medium, which greatly restricts their usage especially in biochemical analysis. To address above challenges, we developed gold nanoparticles/calcium hexacyanoferrate (Ⅲ)/nitrogen-doped graphitic alkyne (AuNPs/CaHF NPs/N-GDY) nanozyme with superior cascade catalytic activity at neutral pH comparable to that of acidic. Specifically, AuNPs/CaHF NPs/N-GDY simultaneously possessed glucose oxidase-like (GOx) and peroxidase-like (HRP) activities, which could induce one-step cascade reaction in the presence of glucose, resulting in 5-fold enhancement in catalytic efficiency compared with conventional two-step cascade reaction. Besides, tripedal DNA walker was equipped with sufficient walking legs to walk on directional and highly controllable stepped track, reducing the possibility of derailment and boosting walking efficiency. As a proof of concept, a novel electrochemical biosensor was constructed for miRNA-21 sensitive detection at physiological pH, and successfully applied in human serum samples as well as practical intracellular analysis, offering great potential in biomedical research and clinical diagnosis.

Many biosensor technologies that can precisely and sensitively identify biomarkers reflecting disease status are being developed to help with early cancer detection and anticancer treatment monitoring. The creation of sensors based on nanozymes is one of the novel approaches in the intricate diagnosis and treatment of cancers. Because natural enzyme sensors can be unstable and expensive, the use of nanozymes in biosensors offers a great substitute for this type of study. Nanozymes have a stable shelf life, great operational reliability, cheap cost, and outstanding catalytic activity. The technological approaches to generating nanozymes and their use in sensors are briefly described in the paper. A summary of the many kinds of biosensors based on diverse kinds of nanomaterials for the identification of cancer biomarkers is provided, along with a discussion of the latest developments and challenges in the field of nanozyme biosensors for use in cancer diagnosis.

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.