Hydrogen peroxide (H2O2) is a key molecule in numerous physiological, industrial, and environmental processes. H2O2 is monitored using various methods like colorimetry, luminescence, fluorescence, and electrochemical methods. Here, we aim to provide a comprehensive review of solid state sensors to monitor H2O2. The review covers three categories of sensors: chemiresistive, conductometric, and field effect transistors. A brief description of the sensing mechanisms of these sensors has been provided. All three sensor types are evaluated based on the sensing parameters like sensitivity, limit of detection, measuring range and response time. We highlight those sensors which have advanced the field by using innovative materials or sensor fabrication techniques. Finally, we discuss the limitations of current solid state sensors and the future directions for research and development in this exciting area.
Microfluidic devices have been conventionally fabricated using traditional photolithography or through the use of soft lithography both of which require multiple complicated steps and a clean room setup. Xurography is an alternative rapid prototyping method which has been used to fabricate microfluidic devices in less than 20–30 minutes. The method is used to pattern two-dimensional pressure-sensitive adhesives, polymer sheets, and metal films using a cutting plotter and these layers are bonded together using methods including adhesive, thermal, and solvent bonding. This review discusses the working principle of xurography along with a critical analysis of parameters affecting the patterning process, various materials patterned using xurography, and their applications. Xurography can be used in the fabrication of microfluidic devices using four main approaches: making multiple layered devices, fabrication of micromolds, making masks, and integration of electrodes into microfluidic devices. We have also briefly discussed the bonding methods for assembling the two-dimensional patterned layers. Due to its simplicity and the ability to easily integrate multiple materials, xurography is likely to grow in prominence as a method for fabrication of microfluidic devices.