Chair Measurement and Sensor Technology, Department of Electrical Engineering and Information Technology, Chemnitz University of Technology, 09107 Chemnitz, Germany.
Analysis of Solid Surfaces, Institute for Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany.
Sensors (Basel). 2023 Mar 9;23(6):2961. doi: 10.3390/s23062961.
The transition of electrochemical sensors from lab-based measurements to real-time analysis requires special attention to different aspects in addition to the classical development of new sensing materials. Several critical challenges need to be addressed including a reproducible fabrication procedure, stability, lifetime, and development of cost-effective sensor electronics. In this paper, we address these aspects exemplarily for a nitrite sensor. An electrochemical sensor has been developed using one-step electrodeposited (Ed) gold nanoparticles (EdAu) for the detection of nitrite in water, which shows a low limit of detection of 0.38 µM and excellent analytical capabilities in groundwater. Experimental investigations with 10 realized sensors show a very high reproducibility enabling mass production. A comprehensive investigation of the sensor drift by calendar and cyclic aging was carried out for 160 cycles to assess the stability of the electrodes. Electrochemical impedance spectroscopy (EIS) shows significant changes with increasing aging inferring the deterioration of the electrode surface. To enable on-site measurements outside the laboratory, a compact and cost-effective wireless potentiostat combining cyclic and square wave voltammetry, and EIS capabilities has been designed and validated. The implemented methodology in this study builds a basis for the development of further on-site distributed electrochemical sensor networks.
电化学传感器从基于实验室的测量向实时分析的转变需要特别注意除了新传感材料的经典开发之外的不同方面。需要解决几个关键挑战，包括可重复的制造工艺、稳定性、寿命以及具有成本效益的传感器电子设备的开发。在本文中，我们将以亚硝酸盐传感器为例来解决这些问题。我们使用一步电沉积（Ed）金纳米粒子（EdAu）开发了一种用于检测水中亚硝酸盐的电化学传感器，该传感器的检测限低至 0.38µM，并且在地下水分析中具有出色的分析性能。对 10 个实际传感器进行的实验研究表明，该传感器具有非常高的重现性，能够实现大规模生产。通过 160 个周期的日老化和循环老化对传感器漂移进行了全面研究，以评估电极的稳定性。电化学阻抗谱（EIS）显示出随着老化的增加而发生的显著变化，表明电极表面恶化。为了能够在实验室外进行现场测量，设计并验证了一种紧凑且具有成本效益的无线电化学工作站，它结合了循环伏安法、方波伏安法和电化学阻抗谱法。本研究中实施的方法为进一步开发现场分布式电化学传感器网络奠定了基础。
