School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
Biosensors (Basel). 2023 Aug 17;13(8):827. doi: 10.3390/bios13080827.
Glutathione (GSH) is the most abundant low-molecular-weight biological thiol in vivo and has been linked to several diseases. The accurate quantification of GSH is therefore crucial for disease diagnosis and monitoring. In this study, we prepared self-assembled Cu(I)-Cys (cysteine) nanozymes through a two-step procedure. The Cu(I)-Cys nanoparticles exhibited peroxidase-mimicking activity. Upon the addition of HO, they were able to oxidize 3,3,5,5-tetramethylbenzidine (TMB) into oxTMB, resulting in a measurable increase in UV-Vis absorption at 655 nm. However, in the presence of GSH, oxTMB was reduced back to TMB, leading to a decrease in UV-Vis absorption at 655 nm. By utilizing these changes in the absorption intensity, we achieved the sensitive detection of GSH with a detection limit of 2.13 μM. Moreover, taking advantage of the different peroxidase-mimicking activities of Cu(I)-Cys nanoparticles at various pH values, a sensor array with Cu(I)-Cys nanoparticles at pH 4 and pH 5 was constructed. The discrimination of GSH among Cys and ascorbic acid was achieved and the practicability of the sensor array in human serum was validated. This novel approach holds significant promise for the precise discrimination and quantification of GSH and its potential applications in disease diagnosis and therapeutics.
谷胱甘肽（GSH）是体内最丰富的低分子量生物硫醇，与多种疾病有关。因此，准确测定 GSH 对疾病的诊断和监测至关重要。在本研究中，我们通过两步法制备了自组装的 Cu（I）-Cys（半胱氨酸）纳米酶。Cu（I）-Cys 纳米颗粒表现出过氧化物酶模拟活性。在加入 HO 后，它们能够将 3,3,5,5-四甲基联苯胺（TMB）氧化为 oxTMB，导致在 655nm 处可测量的紫外-可见吸收增加。然而，在 GSH 的存在下，oxTMB 被还原回 TMB，导致在 655nm 处的紫外-可见吸收减少。利用吸收强度的这些变化，我们实现了对 GSH 的灵敏检测，检测限为 2.13μM。此外，利用 Cu（I）-Cys 纳米颗粒在不同 pH 值下不同的过氧化物酶模拟活性，构建了一个在 pH 4 和 pH 5 下含有 Cu（I）-Cys 纳米颗粒的传感器阵列。实现了对 Cys 和抗坏血酸中 GSH 的区分，并验证了传感器阵列在人血清中的实用性。这种新方法有望实现对 GSH 的精确区分和定量，及其在疾病诊断和治疗中的潜在应用。
