Microcontact-BSA imprinted capacitive biosensor for real-time, sensitive and selective detection of BSA

• Microcontact imprinting of proteins on a sensor chip was used.
• High sensitivity was observed.
• Selectivity was equal to or better than that of antibodies.
• Stability of the sensor chip was very high.

An analytical method is presented, combining novel microcontact imprinting technique and capacitive biosensor technology for the detection of BSA. Glass cover slips were used for preparation of protein stamps. The microcontact-BSA imprinted gold electrodes were prepared in the presence of methacrylic acid (MAA) and poly-ethylene glycol dimethacrylate (PEGDMA) as the cross-linker by bringing the protein stamp and the gold electrode into contact under UV-polymerization. Real-time BSA detection studies were performed in the concentration range of 1.0 × 10−20–1.0 × 10−8 M with a limit of detection (LOD) of 1.0 × 10−19 M. Cross-reactivity towards HSA and IgG were 5 and 3%, respectively. The electrodes were used for >70 assays during 2 months and retained their binding properties during all that time. The NIP (non-imprinted) electrode was used as a reference. The microcontact imprinting technology combined with the biosensor applications is a promising technology for future applications.