Impedimetric Gram-Positive Bacteria Biosensor Using Vancomycin-Coated Silica Nanoparticles with a Gold Nanocluster-Deposited Electrode

• Published in: Analytical chemistry (Washington) Vol. 96; no. 42; pp. 16658 - 16667
• Main Authors: Tieu, My-Van, Abafogi, Abdurhaman Teyib, Hoang, Thi Xoan, Pham, Duc-Trung, Park, Jaehwan, Park, Sungho, Park, Sungsu, Cho, Sungbo
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.10.2024
• Subjects: Bacteria; Biosensors; Circuit boards; Coliforms; E coli; Electrochemical impedance spectroscopy; Electrochemistry; Electrodes; Electroplating; Gold; Gram-negative bacteria; Gram-positive bacteria; Nanoclusters; Nanoparticles; Polymerase chain reaction; Printed circuits; Real time; Silica; Silicon dioxide; Spectroscopy; Vancomycin; Water analysis; Water sampling
• ISSN: 0003-2700; 1520-6882; 1520-6882
• DOI: 10.1021/acs.analchem.4c02852

We introduce a swift, label-free electrochemical biosensor designed for the precise on-site detection of Gram-positive bacteria via electrochemical impedance spectroscopy. The biosensor was prepared by electroplating the electrode surface with gold nanoclusters (AuNCs) on the gold-interdigitated wave-shaped electrode with a printed circuit board (Au-PCB) electrode, which plays a role in cost-effective and promising lab-on-a-chip microsystems and integrated biosensing systems. This was followed by the application of silica nanoparticle-modified vancomycin (SiNPs-VAN) that binds to Gram-positive bacteria and facilitates their detection on the AuNC-coated surface. The biosensor demonstrated remarkable sensitivity and specificity. It could detect as few as 102 colony-forming units (CFU)/mL of Staphylococcus aureus, 101 CFU/mL of Bacillus cereus, and 102 CFU/mL of Micrococcus luteus within 20 min. Additionally, SiNPs-VAN is also known for its high stability, low cost, and ease of preparation. It is effective in identifying Gram-positive bacteria in water samples across a concentration range of 102–105 CFU/mL and shows selective identification of Gram-positive bacteria with minimal interference from Gram-negative bacteria like Escherichia coli. The ability of the biosensor to quantify Gram-positive bacteria aligns well with the results obtained from the quantitative real-time polymerase chain reaction (qRT-PCR). These findings highlight the potential of electrochemical biosensors for the detection of pathogens and other biological entities, marking a significant advancement in this field.