Dual Synthetic Receptor-Based Sandwich Electrochemical Sensor for Highly Selective and Ultrasensitive Detection of Pathogenic Bacteria at the Single-Cell Level

Abstract

Sensitive and rapid detection of pathogenic bacteria is essential for effective source control and prevention of microbial infectious diseases. However, it remains a substantial challenge to rapidly detect bacteria at the single-cell level. Herein, we present an electrochemical sandwich sensor for highly selective and ultrasensitive detection of a single bacterial cell based on dual recognition by the bacteria-imprinted polymer film (BIF) and aptamer. The BIF was used as the capture probe, which was in situ fabricated on the electrode surface within 15 min via electropolymerization. The aptamer and electroactive 6-(Ferrocenyl)­hexanethiol cofunctionalized gold nanoparticles (Au@Fc-Apt) were employed as the signal probe. Once the target bacteria were anchored on the BIF-modified electrode, the Au@Fc-Apt was further specifically bound to the bacteria, generating enhanced current signals for ultrasensitive detection of Staphylococcus aureus down to a single cell in phosphate buffer solution. Even in the complex milk samples, the sensor could detect as low as 10 CFU mL–1 of S. aureus without any complicated pretreatment except for 10-fold dilution. Moreover, the current response to the target bacteria was hardly affected by the coexisting multiple interfering bacteria, whose number is 30 times higher than the target, demonstrating the excellent selectivity of the sensor. Compared with most reported sandwich-type electrochemical sensors, this assay is more sensitive and more rapid, requiring less time (1.5 h) for the sensing interface construction. By virtue of its sensitivity, rapidity, selectivity, and cost-effectiveness, the sensor can serve as a universal detection platform for monitoring pathogenic bacteria in fields of food/public safety.

The Compact Integration of Multiple Exonuclease III-Assisted Cyclic Amplification Units for High-Efficiency Ratiometric Electrochemiluminescence Detection of MRSA

“…Bacteria have posed a significant threat to the public health security of human society throughout their development. , With the overuse of antibiotics, antibiotic-resistant bacteria have emerged that can even decompose and actively eliminate drugs, posing a significant challenge to the clinical treatment of these pathogens. , Among them, methicillin-resistant Staphylococcus aureus (MRSA) exhibits multiresistance to a plethora of antibiotics, rendering the treatment of MRSA infection as one of the most complex dilemmas. , The conventional techniques for bacterial detection, such as culture counting and PCR, often necessitate prolonged incubation periods and the use of sophisticated equipment, thereby imposing limitations on their clinical applicability . Therefore, the development of reliable MRSA detection methods is essential for the timely implementation of effective infection control measures.…”

ZnO@Ag-Functionalized Paper-Based Microarray Chip for SERS Detection of Bacteria and Antibacterial and Photocatalytic Inactivation

“…Commonly used bacterial identification techniques include plate culture, polymerase chain reaction (PCR), gene chip, second-generation sequencing technology, immunological detection, etc. 2,3 Each of these methods has its own advantages, but they cannot be unified in terms of flexibility, ease of operation, accuracy, and low cost. 4−6 Surface-enhanced Raman scattering (SERS) is a phenomenon in which when an electromagnetic field on the surface of a precious metal-enhanced substrate is placed close to nanoparticles (NPs) such as gold and silver, it significantly amplifies the intrinsic molecular vibrational fingerprint (i.e., Raman spectrum) of the detected object.…”

“…In routine food inspection, accurate and sensitive detection of pathogenic microbial contamination is essential. Commonly used bacterial identification techniques include plate culture, polymerase chain reaction (PCR), gene chip, second-generation sequencing technology, immunological detection, etc. , Each of these methods has its own advantages, but they cannot be unified in terms of flexibility, ease of operation, accuracy, and low cost. − …”

Simultaneous Electrochemical Detection of Multiple Bacterial Species Using Metal–Organic Nanohybrids

“…Electrochemical biosensors are particularly useful in fields where on-site inspection is required because of their high sensitivity, rapid measurement, and ease of device miniaturization. − Generally, biosensors use electrochemical reporters as labels to obtain electrochemical signals. These electrochemical reporters include ferrocene, methylene blue, enzymes (e.g., horseradish peroxidase and glucose oxidase), and metal complexes (e.g., ruthenium and osmium complexes). − More recently, many new detection principles have been developed to improve specificity, sensitivity, and simplicity and enable rapid detection. − In particular, metal nanoparticles have been used in biosensor design owing to their characteristic surface effects and catalytic functions. − However, it is necessary to separate electrochemical cells for different labels or to fabricate a multiarray of electrodes that is selective for bacterial species when multiple bacterial species need to be detected simultaneously.…”