DEVELOPMENT OF PRINTED CIRCUIT BOARD BASED ELECTROCHEMICAL BIOSENSOR POSTFABRICATION METHOD

• Main Author: Novianti Hasanah, Astrid
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80964
• Institution: Institut Teknologi Bandung

Electrochemical biosensors are tools for testing the presence of analytes in samples. A common sensor fabrication technique is thick film fabrication such as screen printing. Apart from this fabrication technique, there is the development of thin film fabrication techniques using industrial processes on printed circuit board (PCB) substrates. PCB-based fabrication techniques have several advantages with fabrication precision and the potential for good integration capabilities with electronic components. However, industrial processes can leave behind contaminants and specifications that are not fully suited to the needs of sensor applications. Thus, a sensor post-fabrication method is needed before sensor applications. In this final project, a post-fabrication method for sensors is developed on a PCB substrate with a gold working electrode (WE) and a gold counter electrode (CE) and a silver reference electrode (RE). There are various experiments to determine the method of plating, cleaning, and forming the Ag/AgCl reference electrode. The sensor goes through a plating process to re-coat the silver metal on the RE. The plating method chosen was electroless immersion plating for 8 hours. The sensor goes through a cleaning process to reduce contamination on the surface layer of the sensor electrode. The cleaning method chosen was sonication for 5 minutes in acetone and distilled water solution. The sensor also goes through a chlorination process to form an Ag/AgCl layer on the RE. There are two variations of the Ag/AgCl reference electrode formation method. Method evaluation was carried out using SEM and EDX of the sensor surface. The measurement results were tested on two analytes such as PB and K3[Fe(CN)6] with CV, LSV, and CA techniques. PCB sensors showed better selectivity when compared with commercial sensors, based on CV characteristics that are more similar to reference. PCB sensors also exhibited a higher linearity value (R2 = 0,998).