Kumar Jitender, Roy Indrajit
Department of Chemistry, University of Delhi, Delhi 110007, India.
ACS Omega. 2022 Aug 17;7(34):29840-29849. doi: 10.1021/acsomega.2c02671. eCollection 2022 Aug 30.
Detection of Sn ions in environmental and biological samples is essential owing to the toxicological risk posed by excess use tin worldwide. Herein, we have designed a nanoprobe involving upconversion nanophosphors linked with a rhodamine-based fluorophore, which is selectively sensitive to the presence of Sn ions. Upon excitation with near-infrared (NIR) light, the green emission of the nanophosphor is reabsorbed by the fluorophore with an efficiency that varies directly with the concentration of the Sn ions. We have explored this NIR-excited fluorescence resonance energy transfer (FRET) process for the quantitative and ratiometric detection of Sn ions in an aqueous phase. We have observed an excellent linear correlation between the ratiometric emission signal variation and the Sn ion concentration in the lower micromolar range. The detection limit of Sn ions observed using our FRET-based nanoprobe is about 10 times lower than that observed using other colorimetric or fluorescence-based techniques. Due to the minimal autofluorescence and great penetration depth of NIR light, this method is ideally suited for the selective and ultrasensitive detection of Sn ions in complex biological or environmental samples.
由于全球范围内锡的过度使用带来毒理学风险，检测环境和生物样品中的锡离子至关重要。在此，我们设计了一种纳米探针，它由与罗丹明基荧光团相连的上转换纳米磷光体组成，对锡离子的存在具有选择性敏感性。在用近红外（NIR）光激发时，纳米磷光体的绿色发射被荧光团重新吸收，其效率与锡离子浓度直接相关。我们探索了这种近红外激发的荧光共振能量转移（FRET）过程，用于水相中锡离子的定量和比率检测。我们观察到在较低微摩尔范围内，比率发射信号变化与锡离子浓度之间存在良好的线性相关性。使用我们基于FRET的纳米探针观察到的锡离子检测限比使用其他比色法或荧光法技术观察到的检测限低约10倍。由于自发荧光最小且近红外光穿透深度大，该方法非常适合在复杂生物或环境样品中选择性和超灵敏地检测锡离子。
