Gong Xue, Cai Qingqing, Zhang Jiajia, Min Yuanhong, Fu Wensheng, Wang Yi, Zhang Pu
Engineering Research Center for Biotechnology of Active Substances (Ministry of Education), Chongqing Key Laboratory of Green Synthesis and Applications, College of Chemistry, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing, 400016, China.
Mikrochim Acta. 2023 Feb 24;190(3):104. doi: 10.1007/s00604-023-05686-2.
Inorganic pyrophosphate anions (PPi) play a key role in various biological processes and act as an essential indicator for physiological function evaluation and disease diagnosis. However, there is still a lack of available approaches for straightforward, robust, and convenient PPi detection. Herein, we design an on-off-on fluorescent switching nanoprobe employing Fe-mediated fluorescent sulfur quantum dots (SQDs) for highly robust detection of PPi. The bovine serum protein (BSA)-capped SQDs with fine water dispersibility and good optical stability are synthesized by an HO-assisted chemical etching reaction. Specifically, Fe can strongly induce the aggregation of the SQDs into relatively larger sizes, resulting in aggregation-induced fluorescence quenching behavior. PPi can selectively bind with Fe via emulative coordination and in preventing the aggregation of SQDs this is accompanied by recovery of fluorescence. The physicochemical properties of aggregated and disaggregated SQDs have been systematically investigated. Aggregation and disaggregation of the SQDs and the corresponding quenching and recovery of fluorescence occurs and guarantees the high-contrast sensing performance of the SQD system in complex and challenging aquatic environments. Our designed on-off-on nanoswitch holds great potential for the design of elemental quantum dot-based biosensors for the highly robust detection of analytes in the near future.
无机焦磷酸阴离子（PPi）在各种生物过程中起着关键作用，是生理功能评估和疾病诊断的重要指标。然而，目前仍缺乏直接、可靠且便捷的PPi检测方法。在此，我们设计了一种开-关-开型荧光切换纳米探针，采用铁介导的荧光硫量子点（SQDs）对PPi进行高灵敏度检测。通过羟基辅助化学蚀刻反应合成了具有良好水分散性和光学稳定性的牛血清蛋白（BSA）包覆的SQDs。具体而言，铁能强烈诱导SQDs聚集形成相对较大的尺寸，导致聚集诱导荧光猝灭行为。PPi可通过竞争性配位与铁选择性结合，防止SQDs聚集，同时伴随荧光恢复。系统研究了聚集和分散状态下SQDs的物理化学性质。SQDs的聚集和解聚以及相应的荧光猝灭和恢复现象的发生，保证了SQD系统在复杂且具有挑战性的水环境中的高对比度传感性能。我们设计的开-关-开型纳米开关在不久的将来为基于元素量子点的生物传感器设计用于高灵敏度检测分析物具有巨大潜力。
