Nuclease Triggered “Signal-On” and Amplified Fluorescent Sensing of Fumonisin B1 Incorporating Graphene Oxide and Specific Aptamer

Abstract

Remarkable advancements have been achieved in the development of rapid analytic techniques toward fumonisin B1 (FB1) monitoring and even trace levels for food safety in recent years. However, the point-of-care testing for quantitative and accurate FB1 determination is still challenging. Herein, an innovative aptasensor was established to monitor FB1 by utilizing graphene oxide (GO) and nuclease-triggered signal enhancement. GO can be utilized as a fluorescence quenching agent toward a fluorophore-modified aptamer, and even as a protectant of the aptamer from nuclease cleavage for subsequent target cycling and signal amplification detection. This proposed sensing strategy exhibited a good linearity for FB1 determination in the dynamic range from 0.5 to 20 ng mL−1 with a good correlation of R2 = 0.995. Its limit of detection was established at 0.15 ng mL−1 (S/N = 3), which was significantly lower than the legal requirements by three orders of magnitude. The interferent study demonstrated that the introduced aptasensor possessed high selectivity for FB1. Moreover, the aptasensor was successfully applied to the detection of wheat flour samples, and the results were consistent with the classical ELISA method. The rapid response, sensitive and selective analysis, and reliable results of this sensing platform offer a promising opportunity for food mycotoxin control in point-of-care testing.

Nanomaterials-Based Biosensors against Aspergillus and Aspergillosis: Control and Diagnostic Perspectives

“…Aptamer, considered as chemical antibody and even superior to antibody, can recognize the target molecule to form unique 3D configuration with high affinity and selectivity [6,7]. Accordingly, aptasensors have attracted increasing attention in recent years toward a variety of target molecules including proteins, cells, viruses, bacteria, metal ions, as well as the disease biomarkers [8,9].…”

“…In this effort, GO was embedded for fluorescent quenching and acted as a protectant of the specific aptamer from nuclease cleavage. The target cycling was then triggered for signal amplification and improved detection sensitivity [9].…”

Aptamers: Functional-Structural Studies and Biomedical Applications 2.0

“…Aptamers are also successfully exploited in the development of biosensors for the rapid, on-site, real-time, and cost-effective monitoring of toxins, bacteria, viruses, etc. For example, for the detection in food of fumonisin B 1 (FB 1 ), a highly toxic and abundant carcinogenic mycotoxin, an aptasensor was developed using a nuclease-triggered signal enhancement and graphene oxide as a fluorescence quenching agent towards a fluorophoremodified FB 1 aptamer [7]. Furthermore, an aptamer library specific for Roseburia intestinalis bacterium, whose changes in its intestinal abundance can cause obesity, enteritis, and atherosclerosis, has been selected, containing potential candidates for the construction of electronic biosensors to be used in the monitoring of R. intestinalis in gut microbiomes [8].…”