Lanthanum strontium cobalt ferrite [La0.6Sr0.4Co0.2Fe0.8O3-δ] alloyed impedimetric sensing platform for human papillomavirus type 16 mutant DNA detection

Abstract

Human papillomavirus type 16 (HPV-16) is a leading cause of cervical cancer among women worldwide. This study presents an electrochemical impedance spectroscopy (EIS)-based biosensor for the sensitive and selective detection of HPV-16 mutant DNA. A single-stranded DNA probe complementary to the target sequence was immobilized on a gold interdigitated electrode (G-IDE) modified with lanthanum strontium cobalt ferrite La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) nanopowder to enhance charge transfer. The synthesized LSCF, composed of ∼32 nm discrete cubic particles, was characterized by electron microscopy, XRD, and SAED, confirming its crystalline structure. FTIR indicated metal-oxygen bonding, while Raman spectroscopy revealed oxygen and carbon non-stoichiometry in the perovskite. The developed sensor achieved a limit of detection of 0.0213 fM, with a tested detection range from 1 fM to 1 nM and a linear dynamic range from 1 fM to 100 pM (R2 = 0.9983). Selectivity was confirmed using mismatch and non-complementary strands, which produced negligible impedance changes. These results demonstrate the potential of the LSCF-G-IDE biosensor as a promising platform for future point-of-care HPV diagnostics.