Ultrasensitive Detection of Bacteria Using a 2D MOF Nanozyme-Amplified Electrochemical Detector

Abstract

Bacterial infection is one of the major causes of human death worldwide. To prevent bacterial infectious diseases from spreading, it is of critical importance to develop convenient, ultrasensitive, and cost-efficient methods for bacteria detection. Here, an electrochemical detector of a functional two-dimensional (2D) metal–organic framework (MOF) nanozyme was developed for the sensitive detection of pathogenic Staphylococcus aureus. A dual recognition strategy consisting of vancomycin and anti-S. aureus antibody was proposed to specifically anchor S. aureus. The 2D MOFs with excellent peroxidase-like activity can efficiently catalyze o-phenylenediamine to 2,2-diaminoazobenzene, which is an ideal electrochemical signal readout for monitoring the bacteria concentration. Under optimal conditions, the present bioassay provides a wide detection range of 10–7.5 × 107 colony-forming units CFU/mL with a detection limit of 6 CFU/mL, which is better than most of the previous reports. In addition, the established electrochemical sensor can selectively and accurately identify S. aureus in the presence of other bacteria. The present work provides a new pathway for sensitive and selective detection of S. aureus and presents a promising potential in the realm of clinical diagnosis.

2D MOF Periodontitis Photodynamic Ion Therapy

“…Metal–organic frameworks (MOFs) have crystalline porous structures by controllable and ordered coordination of metal nodes and organic linkers. − Numerous studies on MOFs for biomedical applications have been reported recently due to their controllable porous structures and excellent biocompatibility, including phototherapies and nanocarriers for drug loading. − Thus, porphyrin-based MOFs may achieve optimized photonic functionality and light-harvesting ability of porphyrins due to the synergistic effect of metal–linker bridging units. Besides, 2D nanosheets have the advantage of abundant active sites, excellent light-harvesting network, and fast energy migration due to a relatively large surface area. − Therefore, a 2D porphyrinic MOF can be an ideal PDT candidate for treating various clinical diseases including periodontitis. Nevertheless, the limited efficiency of charge transfer and separation also limits the photocatalytic activity. , Surface engineering may provide an effective strategy to optimize the photocatalytic activity of 2D MOFs.…”

Recent Advances in Metal-Organic Framework-Based Electrochemical Biosensing Applications

“…The 2D MOF solidified with S. aureus antibody was the second indication of accurate identification. The functional 2D MOF nanozyme exerts a potent catalytic effect on H 2 O 2 , generating hydroxyl radicals (·OH) that trigger the oxidation of o -phenylenediamine to complete the electrical signal transduction ( Hu et al, 2021 ). Subsequently, a platform capable of the dual signal determination of S. aureus was established ( Figure 2F ).…”

Biocatalytic Metal‐Organic Frameworks: Promising Materials for Biosensing

“…Moreover, a dual identification method (vancomycin as well as anti‐ S. aureus antibody) was proposed to enhance the selectivity of this system toward S. aureus . Thus, the designed electrochemical sensing platform had the ability to accurately, sensitively, and selectively recognize S. aureus [54] …”

“…Thus, the designed electrochemical sensing platform had the ability to accurately, sensitively, and selectively recognize S. aureus. [54] It is worth mentioning that nanochannels as an emerging electrochemical method, have aroused ever-growing research interests in biosensing field, especially in biocatalytic MOFsbased sensing platforms. [55] In response, Song et al proposed a MOFs-in-nanochannels to monitor the enzyme performance on site by growing ZIF-8 with cytochrome C encapsulation on the nanochannel structure of TiO 2 membrane (Figure 4C).…”