## 1 Introduction  
Sensor technology has emerged as a critical foundation for the era of information technology, along with advances in science and technology. A sensor device can convert environmental events into measurable signs that impact various fields of everyday life. Within the realm of sensors, biological and chemical sensors are a small branch but play a necessary role in a wide range of research, leading to the development of various methods such as electrochemical, electronic, optical, and mechanical techniques. However, meeting the increasing demands of reducing product costs, improving sensitivity, and increasing sensor performance is still challenging. To accommodate these requirements, electrochemical (EC)and photoelectrochemical (PEC) sensors have seen particularly noteworthy developments, driven by parallel progress in materials science [1; 2]. EC and PEC methods are two widely researched sensing techniques for analytical applications. They share similar characteristics, including the signal conversion mechanism, the basic components in measurement instrumentation, and a wide range of applications. The working principle of EC-based and PEC-based sensors is shown in Figure 1 with the measurement device called a potentiostat in the conventional three-electrode configuration, including the reference electrode (RE), counter electrode (CE), and working electrode (WE). The mechanism of these sensors hinges on the interaction between a target species and the sensor's catalytic material surface-coated on the WE, facilitating target identification in which both rely on converting chemical signals into electrical signals. Research efforts in these fields are mainly directed towards diversifying sensor materials, utilizing different types and structural forms of nanomaterials with or without labels to enhance identification performance, sensitivity, and specificity in the analysis of interest [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11]. Consequently, EC and PEC sensors have become powerful tools in analytical chemistry, offering broad applicability in diverse fields such as food safety [5; 12; 13; 14; 15; 16; 17; 18], environmental monitoring [19; 20; 21; 22; 23], and health diagnostics [3; 18; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34]. EC sensors function by using receptors immobilized on the surface of the electrode. When an external potential signal is applied, these receptors facilitate redox reactions with target analytes that are adsorbed or bound to the electrode surface. The EC sensor was first reported more than a century ago when [PERSON] demonstrated the glass electrode for pH sensitivity [35]. EC sensors continue to be actively developed due to their diverse reported signals and the low detection limits in theory [36]. EC-based techniques allow for the obtaining of different signals, including voltage, current, and impedance signals, leading to the emergence of many measurement techniques, such as amperometry, potentiometry, voltammetry, and impedimetry. In addition, the same electrical form of the stimulated signal and the collected signal of the EC sensors leads to easy miniaturization of the measurement systems, making them flexible and reducing the cost. Due to their flexibility, reliability, fast response, and cost-effectiveness, EC sensors are ideal for point-of-care (POC) applications such as the ubiquitous glucose meter [37; 38; 39; 40]. In addition, electrochemical sensors have also been widely used in industrial and civil environments to detect toxic gases [41]. In recent years, strategies for the development of EC sensors have been related to enhancing selectivity and detection limits [42; 43; 44] alongside the discipline of nanoscience and nanotechnology. Figure 1: The working principle of EC-based and PEC-based sensors. In addition to the advantages of EC-based sensors, they also have limitations. The electrical consistency of the stimulation and collection signals can limit the sensitivity due to background noise from the excitation signal.