Photoelectrochemical biosensors for the detection of colorectal cancer biomarkers

Abstract

Colorectal cancer (CRC) is the third most common cause of cancer related deaths worldwide. The gold standard of screening is colonoscopy, which though sensitive is highly invasive and expensive. Faecal immunochemical testing is sometimes used to complement the colonoscopy technique, and is sensitive and affordable but less effective for early-stage CRC detection. There has been extensive research on the development of non-invasive techniques with high accuracy. Biomarkers have found application in the detection and characterization of CRC for improved prognosis. These are quantifiable proteins, gene mutations and circulating tumour cells, all released by the body as a result of the presence of a tumour within the body. Biosensors are analytical devices which include a biological element and produce a signal relative to the analyte. Photoelectrochemical (PEC) biosensors are light based electrochemical sensors, whose sensitivity is determined by the (i) photoactive material, (ii) biorecognition and (iii) mechanism of detection. In this chapter, the application of PEC for CRC biomarker detection is discussed. The progress, gaps and future prospects in PEC biosensor design for biomarker detection are also outlined.