Ultrasensitive electrochemical detection of phospholipase C via dual signal amplification based on MVL ATRP and silver nanoparticles

An ultrasensitive electrochemical sensor for phospholipase C (PLC) was developed via dual signal amplification based on metal-free visible-light induced atom transfer radical polymerization (MVL ATRP) and Ag nanoparticles (AgNPs). The environment-friendly MVL ATRP method was used to form aldehyde based polymers on the electrode surface, providing more reaction sites for further silver mirror reaction. In addition, a large number of electrically active AgNPs were obtained through efficient and low-cost silver mirror reaction, which improved the detection signal. Under the optimal conditions, the proposed sensor showed a linear response from 1 mU/L to 106 mU/L for PLC with a detection limit of 0.1032 mU/L (S/N = 3). Most importantly, the sensor was successfully applied to detect PLC in non-tumor cells (MCF-10A) and tumor cells (MCF-7, MDA-MB-231). The obtained values had no obvious difference with that determined by commercial ELISA kit. When 0.5–10 U/L standard PLC were added into the above cells extracts, the recovery rate was between 96.1% and 102.9%, and the RSD was less than 4.02%. The results showed that the fabricated PLC sensor had acceptable potential in clinical applications.