Sensitive recognition of Shiga toxin using biosensor technology: An efficient platform towards bioanalysis of pathogenic bacterial

Abstract Shiga toxin is one of the most important potential toxins produced by Escherichia coli (E. coli) and Shigella dysenteriae. Binding to the ribosome subunit and preventing protein production is the main function of the Shiga toxin. Till now, some the methods like, culture, microscopic methods, ELISA as well as molecular methods have been used for the monitoring of Shiga toxin. Also, PCR and real-time PCR are the most widely used molecular method for sensitive detection of Shiga toxin, which has high sensitivity and specificity compared to other methods. The need for advanced and expensive equipment, time-consuming, sensitivity, and low specificity are the main disadvantages of common diagnostic methods of Shiga toxin and the bacteria that produce it which limit their application. With the advancement of nanobiotechnology, new diagnostic methods are being developed, of which biosensors are one of the most imperative tools. Biosensors have largely been able to overcome the shortcomings of routine methods. In this review, routine diagnostic methods and their limitation were reviewed. Then, biosensors have been considered as a potential modern diagnostic technology. Next, novel approaches on the biosensing of Shiga toxin were investigated based on the role of advanced nanomaterials. In addition, various strategies such as immune-, geno-, cyto, and enzymatic biosensing of Shiga toxin were surveyed. Also, the role of various labels in the biosensing of Shiga toxin were investigated using various labelled and label-free methods. Also, the critical role of various bioreceptors (electrical, optical, electrochemical, electrochemiluminescence, and photoelectrochemical) conjugation with advanced nanomaterials were studied and compared, critically. Finally, the role of MEMS technology and its integration with biosensing were surveyed for the one-site monitoring of stx in real samples. It is expected that, the biosensor technology can provide a promising strategy for the efficient recognition of Stx and Stx produced bacteria in clinical samples based on bioanalysis.