Two-Dimensional Layered Nanomaterial-Based Electrochemical Biosensors for Detecting Microbial Toxins

Abstract

Toxin detection is an important issue in numerous fields, such as agriculture/food safety, environmental monitoring, and homeland security. During the past two decades, nanotechnology has been extensively used to develop various biosensors for achieving fast, sensitive, selective and on-site analysis of toxins. In particular, the two dimensional layered (2D) nanomaterials (such as graphene and transition metal dichalcogenides (TMDs)) and their nanocomposites have been employed as label and/or biosensing transducers to construct electrochemical biosensors for cost-effective detection of toxins with high sensitivity and specificity. This is because the 2D nanomaterials have good electrical conductivity and a large surface area with plenty of active groups for conjugating 2D nanomaterials with the antibodies and/or aptamers of the targeted toxins. Herein, we summarize recent developments in the application of 2D nanomaterial-based electrochemical biosensors for detecting toxins with a particular focus on microbial toxins including bacterial toxins, fungal toxins and algal toxins. The integration of 2D nanomaterials with some existing antibody/aptamer technologies into electrochemical biosensors has led to an unprecedented impact on improving the assaying performance of microbial toxins, and has shown great promise in public health and environmental protection.

From Small Molecules toward Whole Cells Detection: Application of Electrochemical Aptasensors in Modern Medical Diagnostics

“…That is why a good electrochemical affinity-based biosensor (aptasensor) has to be developed with the use of a conductive physicochemical transducer that is able to selectively distinguish minute changes in receptor layer composition [ 184 ]. The sensitivity and selectivity of electrochemical aptasensors have been significantly improved by the application of nanotechnology and nanomaterials in their construction [ 134 , 148 , 150 , 151 , 152 , 161 , 162 , 179 , 182 , 185 , 186 , 187 , 188 ]. Nanomaterials or their composites were used as transducers for aptamer biosensing or as a label, which resulted in a significant improvement in the sensitivity by both increasing the electrochemical signal and simultaneously decreasing background noise (improved signal-to-noise ratio, S/N).…”

Recent advances in nanomaterials integrated immunosensors for food toxin detection

“…With the development of nanomaterials and biotechnology, electrochemical and optical biosensors integrated with nanomaterial have been widely employed in diagnostic devices. The order of improvements have come under consideration by using the anisotropic nanomaterials for electrode fabrication results to improve the characterstic parameters of the diagnostic device such as sensitivity, specificity, reproducibility, limit of detection and wide detection range (Li et al 2020). When compared with traditional techniques, advances achieved in nanomaterials based biosensor are highly commendable.…”

Development of Two-Dimensional Nanomaterials Based Electrochemical Biosensors on Enhancing the Analysis of Food Toxicants

“…Earlier liquid chromatography-based methods, including high-performance liquid chromatography (HPLC) and high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC/MS/MS), were used for the accurate quantification of toxins [ 11 , 12 ]. Although these methods have more reliability and accuracy, they require expensive laboratory facilities, complex pre-treatment processing of the sample, and skilled operators [ 13 , 14 ]. Due to these drawbacks, HPLC-based methods’ application is limited in the on-site analysis of toxins [ 15 ].…”