Tong Xia, Li Guozhu, Guo Qianyu, Hu Jie, Zhang Baiyan, Liu Sumiao, Guo Jing, Zhang Liyun
Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Third Hospital of Shanxi Medical University, Tongji Shanxi Hospital, Taiyuan, 030032, China.
School of Pharmacy, Shanxi Medical University, Taiyuan, 030001, China.
Mikrochim Acta. 2024 Dec 21;192(1):20. doi: 10.1007/s00604-024-06861-9.
A pasting-3D microfluidic paper-based analytical device (P-3D μPAD) was developed. It enabled an efficient cascade reaction between urate oxidase (UOX) and Fe/Pt-doped carbon nanoparticles (Fe/Pt-CNPs) for visual colorimetric detection of uric acid (UA). The novel Fe/Pt-CNP nanozyme performed high peroxidase-like activity toward 3,3',5,5'-tetramethylbenzidine (TMB) and HO with Michaelis - Menten constants (K) of 0.97 and 2.30 mM, respectively. The UOX-Fe/Pt-CNP system was incorporated into P-3D μPAD: the 1st layer was UOX hydrolysis reaction under alkaline pH, and the 2nd layer was Fe/Pt-CNPs catalyzing HO to oxidize TMB at acidic pH. The separated two layers allowed cascade reaction under different working pH without sacrificing the activity of UOX or Fe/Pt-CNPs. The images were captured and analyzed by the camera and "Color Recognition" application using a smartphone. The linear range of P-3D μPAD for UA was 25-1000 μM with a limit of detection of 10 μM which met the requirements for clinical applications. The high accuracy of P-3D μPAD for UA detection in invasive (blood) and noninvasive (saliva) samples has been confirmed by the biochemical analyzer. This work offers a sensitive, flexible, affordable, and disposable tool for on-site UA level monitoring and provides new insight into natural enzyme and nanozyme tandem systems for biosensing.
一种粘贴式3D微流控纸基分析装置（P-3D μPAD）被开发出来。它能够实现尿酸氧化酶（UOX）与铁/铂掺杂碳纳米颗粒（Fe/Pt-CNPs）之间的高效级联反应，用于尿酸（UA）的可视化比色检测。新型的Fe/Pt-CNP纳米酶对3,3',5,5'-四甲基联苯胺（TMB）和H₂O₂具有高过氧化物酶样活性，其米氏常数（Kₘ）分别为0.97和2.30 mM。UOX-Fe/Pt-CNP系统被整合到P-3D μPAD中：第一层是在碱性pH下的UOX水解反应，第二层是Fe/Pt-CNPs在酸性pH下催化H₂O₂氧化TMB。分离的两层允许在不同的工作pH下进行级联反应，而不会牺牲UOX或Fe/Pt-CNPs的活性。图像通过智能手机的摄像头和“颜色识别”应用程序进行拍摄和分析。P-3D μPAD对UA的线性范围为25-1000 μM，检测限为10 μM，满足临床应用要求。生化分析仪已证实P-3D μPAD在侵入性（血液）和非侵入性（唾液）样本中检测UA的高准确性。这项工作为现场UA水平监测提供了一种灵敏、灵活、经济且一次性使用的工具，并为生物传感的天然酶和纳米酶串联系统提供了新的见解。
