Electrochemical genosensor array for the simultaneous detection of multiple high-risk human papillomavirus sequences in clinical samples

An electrochemical genosensor array for the simultaneous detection of three high-risk human papillomavirus (HPV) DNA sequences, HPV16, 18 and 45, exhibiting high sensitivity and selectivity is presented. The electrodes of a 4 × 4 array were modified via co-immobilization of a 1:100 (mol/mol) mixture of a thiolated probe and an oligoethyleneglycol-terminated bipodal thiol. Detection of synthetic and PCR products was carried out in a sandwich type format, with the target hybridized between a surface immobilized probe and a horseradish peroxidase-labelled secondary reporter probe. The detection limits obtained in the detection of each individual target were in the pM range, allowing the application of this sensor for the detection of samples obtained from PCR amplification of cervical scrape samples. The results obtained exhibited an excellent correlation with the HPV genotyping carried out within a hospital laboratory. Multiplexing and cross-reactivity studies demonstrated high selectivity over potential interfering sequences, facilitating application of the developed platform for the high-throughput screening of multiple high-risk DNA sequences.