Electrical detection of cisplatin-DNA adduct formation using dielectrophoresis-based impedance spectroscopy

Chemicals that form DNA adducts can be carcinogenic; therefore, their detection is essential for cancer research and genotoxicity screening. However, existing methods often require complex instrumentation or electrode modification, highlighting the need for simpler detection approaches. We aimed to develop a simple and rapid method for detecting DNA adduct formation using dielectrophoresis (DEP)-based impedance spectroscopy. Cisplatin was used as a model DNA-adduct-forming agent and incubated with DNA-labeled microbeads. Changes in DEP behavior were analyzed through crossover frequency measurements and impedance spectroscopy during frequency sweeps (200 kHz-10 MHz). Cisplatin treatment under conditions intended to promote DNA adduct formation was associated with a concentration-dependent decrease in the crossover frequency of DNA-labeled microbeads. During frequency sweeps, the conductance changed in the frequency region corresponding to the DEP transition, and the peak frequency derived from the conductance response showed strong agreement with the crossover-frequency trend. Quantitative detection was achieved over 0.05-0.5 mM, with a detection limit of 0.05 mM (50 μM). This DEP-based impedance approach offers a simple, cost-effective alternative to conventional methods that require electrode modification. Although the detection limit requires substantial improvement for future biological or clinical applications, the method provides a simple proof-of-concept platform for preliminary screening and methodological development.