alpha-Synuclein (alpha-Syn) is a pivotal biomarker for Parkinson's disease (PD) and related synucleinopathies. However, the sensitive and selective detection of pathological alpha-Syn remains highly challenging because of its low abundance, structural heterogeneity, and diverse aggregation states. No single analytical platform currently meets all requirements for routine clinical screening. Electrochemical biosensors have emerged as a powerful tool to address these bottlenecks, offering high sensitivity, rapid response, low cost, and great potential for point-of-care testing (POCT). This review systematically summarizes the role of alpha-Syn in PD pathogenesis and highlights recent advances in electrochemical detection strategies, including immunosensors, aptasensors, molecularly imprinted polymers (MIPs), electrochemiluminescence (ECL), photoelectrochemical (PEC) systems, and integrated portable devices. Furthermore, current challenges are emphasized, particularly in low-abundance detection, matrix interference, conformational discrimination, and clinical standardization. Finally, future perspectives in this field are outlined, focusing on multiplex biomarker platforms and artificial intelligence (AI)-assisted analytical strategies for the early diagnosis and management of neurodegenerative diseases.
A mixed anaerobic microbial consortium producing short- and medium-chain fatty acids from CO2 and H2 was developed through mixed culture cultivation under a CO2/H2 atmosphere combined with the serial transfer technique to promote the growth of acetogenic and chain-elongating bacteria. Consequently, this enrichment was used to inoculate laboratory-scale microbial electrosynthesis (MES) cells that were continuously fed with CO2. To improve MES performance, a novel three-dimensional conductive polylactate cathode coated with a NiFeSn alloy was employed in one MES cell, while another MES cell was equipped with a carbon felt (CF) cathode. CO2 conversion and chain elongation were substantially increased in the NiFeSn cell. In this cell, a steady-state volumetric CO2 conversion rate of 2.4 L (Lc d)- 1 was achieved, with corresponding butyrate and caproate production rates of 1 g (Lc d)- 1 and 0.07 g (Lc d)- 1, respectively, at a current density of up to 4 mA cm- 2. The formation of C16-C18 fatty acids was also observed. 16S rRNA amplicon sequencing of the catholytes and cathodic biofilms revealed a significant shift in microbial populations from Clostridium-driven acetogenesis and chain elongation in the enrichment to one most likely driven by the genera Eubacterium, Megasphaera and Caproiciproducens in MES cells.
PIK3CA gene mutations are key drivers in various malignant tumors, and their highly sensitive detection is crucial for tumor diagnosis. This study aims to develop a label-free electrochemical biosensor based on a TiO2@Co/C@Au nanocomposite for highly sensitive detection of the PIK3CA gene. By optimizing the synthesis conditions of the composite, electrode modification process, and hybridization detection parameters, the synergistic effects of multiple components are utilized to enhance electrode conductivity and biomolecule loading capacity. Leveraging the magnetic properties of cobalt enables simple, controllable electrode modification, establishing a "signal-off" detection platform. The sensor has a linear range of 1 fM to 1 mu M and a detection limit of 2.26 fM, enabling low femtomole detection of the PIK3CA gene with excellent specificity, reproducibility, and stability. In real serum sample testing, the sensor demonstrated good recovery rates (99.92%-117.75%), and the measured values closely matched the added concentrations, confirming its reliability and practicality in complex biological matrices. This provides a cost-effective, simple, and reliable new strategy for point-of-care detection of tumor-related genes.
Rapid and sensitive detection of Candida albicans is important for early diagnosis and timely management of fungal infections. Here, we report a precursor-integrated strategy for constructing a flexible Zn-containing laserinduced graphene/cysteamine biointerface, denoted as LIG-ZnO/Cys, functionalized with single-stranded DNA (ssDNA) for the direct detection of intact C. albicans cells. Sodium lignosulfonate was used as a renewable biomass-derived carbon precursor, enabling direct laser formation of a porous conductive LIG framework without a separate carbon-material deposition step. Meanwhile, Zn-containing species were incorporated into the precursor and retained after laser treatment as dispersed Zn-containing domains, which are conservatively referred to as ZnO-related domains in this work, providing Zn-associated sites for subsequent interfacial functionalization. The resulting amino-functionalized surface enabled glutaraldehyde-mediated immobilization of amino-modified ssDNA probes. SEM, EDS, XRD, Raman spectroscopy, XPS, and EIS verified the morphology, composition, surface chemistry, and stepwise assembly of the interface. Target-cell-associated interfacial blocking generated a signal-off DPV response over 1.0 & times; 100-1.0 & times; 106 CFU mL- 1, with a theoretical detection limit of 1.01 CFU mL- 1. The sensor showed good tolerance to the tested small-molecule interferents, a preferential response toward C. albicans, and satisfactory recoveries in the tested biological matrices.
Breast cancer-associated miRNAs are promising liquid-biopsy biomarkers, but their low serum abundance, short sequences and matrix interference hinder sensitive and multiplexed detection. Herein, we developed an Ag NPs@MXene-mediated electrochemical-surface-enhanced Raman scattering (EC-SERS) dual-mode microfluidic array for multiplexed miRNA detection. The platform integrates a multichannel chip, an Au NPs@Au capture interface and an Ag NPs@MXene signal unit loaded with methylene blue (MB) and detection probe P2. In the presence of target miRNAs, the signal unit is recruited to the electrode through a capture unit-miRNA-signal unit sandwich assembly, forming a Faraday-cage-type structure. Conductive MXene nanosheets promote electron transfer and enable abundant MB labels to contribute to electrochemical responses, while Ag NPs enhance the SERS signal of MB. The chip enabled parallel detection of miRNA-21, miRNA-155, miRNA-200c and miRNA-375 over 10-16-10-10 M, with EC and SERS LODs of 0.022-0.042 fM and 0.036-0.067 fM, respectively. Specificity, reproducibility, stability and serum recovery tests confirmed reliable performance. Clinical serum analysis distinguished breast cancer patients from healthy controls with an AUC of 1.000, supporting its potential for breast cancer liquid biopsy.
