State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety (Ministry of Education), College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, China.
Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin, 300071, China.
Anal Bioanal Chem. 2019 Jul;411(18):4093-4101. doi: 10.1007/s00216-018-1439-2. Epub 2018 Nov 7.
Ascorbic acid (AA) detection in biological sample and food sample is critical for human health. Herein, a MnO nanosheet (MnO-NS)-based ratiometric fluorescent nanosensor has been developed for high sensitive and specific detection of AA. The MnO-NS presents peroxidase-like activity and can oxidize non-fluorescent substrate of o-phenylenediamine (OPDA) into fluorescent substrate, presenting maximum fluorescence at 568 nm (F). If MnO-NS is premixed with AA, the MnO-NS is then decomposed as Mn by AA, decreasing the fluorescent intensity of F. Meantime, AA is oxidized as dehydroascorbic acid (DHAA), which can react with OPDA to generate fluorescent substrate. A new fluorescence response is found at 425 nm (F). The dual fluorescent responses can be excited with a universal excitation wavelength, simplifying the detection procedure. With F/F as readout, limit of detection for AA reaches as low as 10.0 nM. Satisfactory recoveries are found for AA detection in serum and diverse beverages. The ratiometric strategy significantly eliminates false-negative and false-positive results, providing a cost-effective, rapid, and reliable way for AA detection in real sample.
抗坏血酸（AA）在生物样本和食品样本中的检测对人类健康至关重要。在此，开发了一种基于 MnO 纳米片（MnO-NS）的比率荧光纳米传感器，用于 AA 的高灵敏和特异性检测。MnO-NS 具有过氧化物酶样活性，可将非荧光底物邻苯二胺（OPDA）氧化成荧光底物，在 568nm 处呈现最大荧光（F）。如果 MnO-NS 与 AA 预先混合，则 MnO-NS 被 AA 分解为 Mn，从而降低 F 的荧光强度。同时，AA 被氧化为脱氢抗坏血酸（DHAA），它可以与 OPDA 反应生成荧光底物。在 425nm 处发现了新的荧光响应（F）。双荧光响应可以用通用的激发波长激发，简化了检测过程。以 F/F 作为读出，AA 的检测限低至 10.0nM。在血清和各种饮料中检测 AA 时，均获得了令人满意的回收率。比率策略显著消除了假阴性和假阳性结果，为实际样品中 AA 的检测提供了一种经济、快速和可靠的方法。
