CRISPR/Cas12-powered electrochemical biosensor for chikungunya virus DNA detection using gold-modified screen-printed carbon electrodes

Background and purpose: Chikungunya virus (CHIKV) remains a health concern because its symptoms overlap with dengue and Zika, often leading to misdiagnosis. Conventional diagnostic methods, including viral isolation, enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR), are time-consuming, costly, and dependent on specialized laboratories. This study aimed to develop a rapid, selective, and sensitive electrochemical biosensor integrated with CRISPR/Cas12 for CHIKV DNA detection. Experimental approach: A CHIKV-specific guide RNA targeting a conserved region of the E1 gene was designed in silico and selected by specificity score (99.15) and E-value (1.7). The platform used a gold particle-modified screen-printed carbon electrode (SPCE/Au) functionalized with a ferrocene-labelled DNA reporter. The electrode was characterized electrochemically, and the biosensor was tested for its response to CHIKV DNA, its selectivity against dengue virus (DENV) and SARS-CoV-2, and its detection performance across target concentrations. Key results: Au deposition enhanced the electrochemical properties of the electrode. Recognition of CHIKV DNA activated the CRISPR/Cas12 complex, whose collateral cleavage of the reporter reduced the ferrocene oxidation signal. The biosensor exhibited a concentration-dependent response over 0.01 to 10 ppb, with a limit of detection of 0.92 ppb and a limit of quantification of 2.77 ppb. The biosensor showed excellent selectivity against CHIKV competitors. Conclusion: This work shows that combining CRISPR/Cas12 collateral cleavage with a ferrocene-labelled reporter on SPCE/Au enables rapid, selective, and sensitive CHIKV detection. Validation with clinical samples is still needed. The platform supports early diagnosis and disease surveillance, in line with Sustainable Development Goal (SDG) 3 (Good Health and Well-being).