Selection and screening of genetically encoded fluorescent protein as a sensor for cancer theranostics

Early detection and evaluation of prognosis in bladder cancer is necessary due to increase in mortality rate and recurrence of cancer. It is important to find a suitable sensor which gives good sensitivity and selectivity for the diagnosis of bladder cancer. We have developed a genetically encoded redox amino acid (Dopa) in green fluorescent protein and fabricated the same on an electrode surface for the selective and sensitive detection of zinc ions. The genetically encoded protein showed better redox activity and metal co-ordination with zinc. The zinc sensor showed linear responses to the protein fabricated electrode with a detection limit of 0.129 nM. The stability of the protein fabricated electrode showed consistent performance. The developed sensor is highly selective and sensitive for detecting zinc ions in real time spiked urine samples and could be applied for bladder cancer diagnostics. © 2022 The Author(s)