Yang Jialin, Yu Ruizhi, Zhang Wanxin, Wang Yijia, Deng Zejun
School of Materials Science and Engineering, State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.
Hunan Key Laboratory for Super Microstructure and Ultrafast Process, School of Physics, Central South University, Changsha 410083, China.
Sensors (Basel). 2025 Jul 2;25(13):4132. doi: 10.3390/s25134132.
Creatinine serves as a crucial diagnostic biomarker for assessing kidney disease. This work developed portable non-enzymatic and multienzyme-modified electrochemical biosensors for the detection of creatinine based on commercial screen-printed carbon electrodes (SPCEs). The non-enzymatic creatinine sensor was constructed by the electrochemical deposition of AuNPs onto the surface of a pre-activated SPCE by electrochemical activation, followed by the surface modification of a Nafion membrane. The developed AuNPs/SCPE exhibited excellent reproducibility, and the proposed Nafion/AuNPs/SPCE sensor showed excellent detection sensitivity and selectivity toward creatinine. In comparison, the enzymatic creatinine biosensor was gradually established by the electrodeposition of a Prussian blue (PB) membrane on the optimal AuNPs/SCPE surface, followed by multi-enzyme cascade modification (which consisted of creatinine amidohydrolase (CA), creatine oxidase (CI) and sarcosine oxidase (SOx)) and drop-casting the Nafion membrane to stabilize the interface. The introduction of a PB interlayer acted as the redox layer to monitor the generation of hydrogen peroxide (HO) produced by the enzymatic reaction, while the Nafion membrane enhanced the detection selectivity toward creatine, and the multi-enzyme cascade modification further increased the detection specificity. Both non-enzymatic and enzymatic creatinine sensors could detect the lowest concentrations of less than or equal to 10 μM. In addition, the efficiency and reproducibility of the proposed composite biosensor were also confirmed by repetitive electrochemical measurements in human serum, which showed a positive linear calibration relation of peak currents versus the logarithm of the concentration between 10 μM and 1000 μM, namely, i (μA) = -7.06 lgC (μM) -5.30, R = 0.996. This work offers a simple and feasible approach to the development of enzymatic and non-enzymatic creatinine biosensors.
肌酐是评估肾脏疾病的关键诊断生物标志物。本研究基于商用丝网印刷碳电极（SPCE）开发了用于检测肌酐的便携式非酶和多酶修饰电化学传感器。非酶肌酐传感器通过电化学活化将金纳米颗粒（AuNPs）电化学沉积到预活化的SPCE表面，随后进行Nafion膜的表面修饰构建而成。所制备的AuNPs/SCPE具有出色的重现性，所提出的Nafion/AuNPs/SPCE传感器对肌酐表现出优异的检测灵敏度和选择性。相比之下，酶促肌酐生物传感器是通过在最佳AuNPs/SCPE表面电沉积普鲁士蓝（PB）膜，随后进行多酶级联修饰（由肌酐酰胺水解酶（CA）、肌酸氧化酶（CI）和肌氨酸氧化酶（SOx）组成）并滴涂Nafion膜以稳定界面逐步构建的。引入的PB中间层作为氧化还原层来监测酶促反应产生的过氧化氢（HO），而Nafion膜提高了对肌酸的检测选择性，多酶级联修饰进一步提高了检测特异性。非酶和酶促肌酐传感器均可检测低至10 μM及以下的浓度。此外，通过在人血清中的重复电化学测量也证实了所提出的复合生物传感器的效率和重现性，其显示出10 μM至1000 μM之间峰电流与浓度对数的正线性校准关系，即i（μA）= -7.06 lgC（μM） -5.30，R = 0.996。本研究为酶促和非酶促肌酐生物传感器的开发提供了一种简单可行的方法。
