Specific Molecular Recognition of Liposome Nanoparticles and Single-particle Electrochemical Detection

Liposomes delivery drug systems show obvious advantages in the treatment of many diseases. Constructing new types of liposome based drugs is of great importance to develop more efficient novel drug delivery systems. Herein, the present work demonstrated that Au microelectrode was chemically modified with avidin through Au-S bond (Avidin-S-Au microelectrode) and liposomes modified with the biotin (Biotin-liposome) were constructed through molecular assembly. Furthermore, an electrochemical detection device was constructed to recognize liposomes through single nanoparticle collision. Compared with pure liposomes, biotin modified liposome displayed a higher collision frequency and intensity with Avidin-S-Au microelectrode. Importantly, with the increasing concentration of biotin-liposome, the collision frequency increases as well. Taking the single liposome collision to the gold microelectrode into account, one can obtain quantitative information of the liposome size and concentration through the frequency and intensity of single nanoparticle collision. These findings represent an unusual case to achieve high sensitivity detection of individual liposomes with poor electrochemical activity and at very low concentration. The present work creates a simple and effective way to detect the stability of liposomes and their interaction with biomembranes.