Development of an aptamer-mimetic sensing probe based on functionalized amylose-CdSe quantum dots for bisphenol-A detection

In this study, phenyl-functionalized amylose (APS) was prepared as an aptamer-mimetic reception element and bonded covalently to CdSe quantum dots (QDs) to develop a "fluorescence-on" probe for BPA detection. The intertwined APS initially caused aggregation of the QDs, leading to low fluorescence intensity. However, upon wrapping BPA molecules with the APS to form inclusion complexes, the fluorescence was recovered due to the expansion of the interparticle distance between the QDs. The APS-QDs probe exhibited high sensitivity and selectivity for BPA over other endocrine-disrupting chemicals (4,4′-BPF, 2,2′-BPF, pyrene, E2, and phenol), and was highly tolerant of inorganic ions (Na+, Cl-, H2PO4-) even at concentrations 105 times higher than BPA. The system responded to BPA within 5.0 min with a wide dynamic range (1.0 ×10−1-1.0 ×105 μg/L) and a low detection limit (3.0 ×10−2 μg/L in DI water, 8.0 ×10−2 μg/L in tap water, and 7.0 ×10−2 μg/L in drinking water). Moreover, regardless of the matrix effect, it achieved a high recovery (95–103%) with low variation (RSD=1.1–2.3%) at low concentrations (1.0 ×10−1-1.0 μg/L) in tap and drinking water, indicating the potential for water quality control.