A comparative study of aptasensor vs. immunosensor for ultrasensitive detection of aflatoxin B1 using Ag-pSi SERS...

Numerous SERS based platforms have been designed to address the emerging need for detecting fungal metabolite contamination in foodstuffs, and specifically the Group 1 carcinogen aflatoxin B1. Herein, 4-aminothiophenol modified silver-coated porous silicon was used as the SERS substrate. Two ratiometric responses were individually assessed upon direct target capture using specific aptamers or antibodies. Under optimized physical features, elevated enhancement factor, wide dynamic range, low detection limits and pronounced recycling capabilities were achieved (7.39 × 10⁷, 0.2-200 ppb, 0.0085 and 0.0110 ppb, 7 and 1 regeneration cycles without impairing the performances for aptasensor and immunosensor, respectively). The accuracy and anti-interference responses in several intricate matrices (maize, peanut, wheat, oats and rice) were compared to a routine HPLC method with equivalent recoveries. Overall, the comparative assessment revealed preferable features of reusability, durability and accuracy of the aptasensor over the immunosensor. Furthermore, the results demonstrate the substantial potential of the proposed SERS substrate for diverse on-site analytical applications using simple and portable monitoring instrumentation.