In this talk, we will present our recent work on low-cost electrochemical DNA biosensors based on ENIG PCB electrodes for wastewater monitoring using portable end-point PCR instruments, without the requirement for qPCR reagents and instrumentation. The sensor is capable of detecting SARS-CoV-2 nucleocapsid gene amplicons at concentrations as low as 10pg/μl and can detect RNA isolated from wastewater collected from a sewage treatment plant in Mumbai, India. The electrodes do not undergo any surface modification and are cost-effective solutions with long shelf-life for wastewater epidemiology. We have also recently developed an immunosensor platform for antigen-antibody based biosensing with these electrodes.