A novel smectite-polymer nanocomposite (SPN) microstrip sensor for rapid quantitative detection of aflatoxins

This paper reports the development of a novel smectite-polymer nanocomposite (SPN) microstrip sensor for both rapid quantification and long-term monitoring of aflatoxins. The smectite was modified with Ba^2002B; cation exchange to improve its aflatoxin adsorption. SPN thin-films were synthesized on silicon substrates via layer-by-layer self-assembly. SPN microstrip arrays were patterned on glass substrates using stencil masks and enclosed in a microfluidic channel. This reduces the diffusion length and the adsorption time of aflatoxins, thereby resulting in fast response time (<; 10 min). A simple fluorometric quantification of aflatoxin concentration based on incident intensity modulation was developed to eliminate the need of a sophisticated fluorometer. A low detection limit of 6.09 ppb and a wide linear range of 5~80 ppb for aflatoxin B₁ have been achieved.