Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas, E-23071, Jaén, Spain.
Mikrochim Acta. 2019 Nov 15;186(12):781. doi: 10.1007/s00604-019-3920-9.
Two methods for the luminescence determination of cysteine (Cys) are presented. They make use of either silver nanoparticles (Ag NPs) or graphene quantum dots (GQDs), both doped with terbium(III). The methods are based on the finding that Cys quenches the green luminescence of Tb(III)-Ag NPs and Tb(III)-GQDs. The excitation/emission maxima are at 306/545 and 257/545 nm, for both nanoprobes, respectively. Response is linear in the 0.28-5.0 μg mL Cys concentration range for the Tb(III)-Ag NP system, and from 0.05-3.0 μg mL for the Tb(III)-GQD system. The respective limits of detection are 0.09 and 0.015 μg mL. The probes were applied to the time-resolved luminometric determination of Cys in (spiked) food supplements and gave satisfactory results. Graphical abstractSchematic representation of the quenching by cysteine (Cys) of the time-resolved luminescence (TSL) of terbium-graphene quantum dots [Tb(III)-GQD] and of terbium-silver nanoparticles [Tb(III)-Ag NP].
介绍了两种用于半胱氨酸（Cys）发光测定的方法。它们分别利用了掺杂铽（III）的银纳米粒子（Ag NPs）或石墨烯量子点（GQDs）。这些方法基于以下发现：Cys 猝灭了 Tb(III)-Ag NPs 和 Tb(III)-GQDs 的绿色发光。对于这两种纳米探针，激发/发射最大值分别为 306/545nm 和 257/545nm。对于 Tb(III)-Ag NP 体系，响应在 0.28-5.0μg mL Cys 浓度范围内呈线性，对于 Tb(III)-GQD 体系，响应在 0.05-3.0μg mL 范围内呈线性。各自的检测限分别为 0.09μg mL 和 0.015μg mL。该探针用于（加标）食品补充剂中 Cys 的时间分辨发光测定，结果令人满意。
