High performance aptasensing platform development through in silico aptamer engineering for aflatoxin B1 monitoring

Due to the technical challenges of small binding aptamer development, reliable computational simulation studies can be considered as effective tools to design novel and high functional mycotoxin aptameric probes. Here, two novel aflatoxin B1(AFB1) binding aptamers were successfully exploited as recognition elements in the lateral flow aptasensors and the reflective phantom interface (RPI) platform. Using the parent aptamer previously designed through genetic algorithm based in silico maturation (ISM) strategy, F20, a new variant, F20-T, was obtained here via coupling truncating strategy and computational simulation approaches. Two aptamer-gold nanoparticle strip biosensors were developed based on the designed probes for the simple and rapid detection of AFB1 in competitive format. The F20-based strip was more sensitive than that exploiting the truncated aptamer, with limits of detection (LOD) of 0.1 and 0.5 ng/mL, respectively. Based on the in silico and experimental selectivity evaluations of both test strips towards other mycotoxins, including aflatoxin B2, M1, G1, G2, Ochratoxin A and Zearalenone, F20-T based test strip revealed higher selectivity for AFB1. Both developed aptasensors successfully detected AFB1 in maize flour within 30 min using a simple strip reader. Exploiting of F20 and F20-T aptamers in an exclusive technology called RPI platform led to successful AFB1 detection, as well. Both designed aptameric probes can be regarded as potential recognition elements to develop screening tools for rapid, low cost and on-site AFB1 detection. Our findings highlighted the reliable and robust application of computational simulation studies for novel small binding aptamer development and consequently open up a much-needed avenue to design various aptasensing platforms in green and cost effective ways.