Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Biosens Bioelectron. 2014 Sep 15;59:370-6. doi: 10.1016/j.bios.2014.04.003. Epub 2014 Apr 8.
We report here a fluorescence quenching based non-enzymatic method for sensitive and reliable detection of free bilirubin in blood serum samples using human serum albumin (HSA) stabilized gold nanoclusters (HSA-AuNCs) as fluorescent probe. The fluorescence of the nanoclusters was strongly quenched by bilirubin in a concentration dependent manner by virtue of the inherent specific interaction between bilirubin and HSA. A strong binding constant of 0.55×10(6) L mole(-1) between the HSA-AuNC and bilirubin was discerned. The nano clusters each with size ~1.0 nm (in diameter) and a core of Au18 were homogeneously distributed in HSA molecules as revealed from the respective high resolution transmission electron microscopic and mass spectroscopic studies. The fluorescence quenching phenomena which obeyed a simple static quenching mechanism, was utilized for interference free detection of bilirubin with minimum detection limit (DL) of 248±12 nM (S/N=3). The fluorescence response of HSA-AuNCs against bilirubin was practically unaltered over a wide pH (6-9) and temperature (25-50 °C) range. Additionally, peroxidase-like catalytic activity of these nanoclusters was exploited for colorimetric detection of bilirubin in serum sample with a DL of 200±19 nM by following the decrease in absorbance (at λ440 nm) of the reaction and its rate constant (Kp) of 2.57±0.63 mL μg(-1) min(-1). Both these fluorometric and colorimetric methods have been successfully used for detection of free bilirubin in blood serum samples.
我们在此报告了一种基于荧光猝灭的非酶法，用于使用人血清白蛋白（HSA）稳定的金纳米簇（HSA-AuNCs）作为荧光探针，灵敏且可靠地检测血清样品中的游离胆红素。由于胆红素与 HSA 之间固有的特殊相互作用，纳米簇的荧光被胆红素浓度依赖性地强烈猝灭。在 HSA-AuNC 和胆红素之间可以分辨出 0.55×10(6) L mole(-1)的强结合常数。纳米簇的每个尺寸约为 1.0 nm（直径），并且核心为 Au18，如各自的高分辨率透射电子显微镜和质谱研究所示，均匀分布在 HSA 分子中。荧光猝灭现象遵循简单的静态猝灭机制，用于在无干扰的情况下检测胆红素，最低检测限（DL）为 248±12 nM（S/N=3）。在广泛的 pH（6-9）和温度（25-50°C）范围内，HSA-AuNCs 对胆红素的荧光响应几乎没有变化。此外，还利用这些纳米簇的过氧化物酶样催化活性，通过检测反应吸光度（在 λ440 nm 处）的降低及其速率常数（Kp）为 2.57±0.63 mL μg(-1) min(-1)，在血清样品中进行胆红素的比色检测，检测限为 200±19 nM。这两种荧光和比色方法都已成功用于检测血清样品中的游离胆红素。
