Characterization of self-assembled monolayers of porphyrins bearing multiple-thiol and photoelectric response

Self-assembled monolayers(SAMs) of thiol-derivatized porphyrin molecules on Au substrate have attracted extensively interest for use in sensing,optoelectronic devices and molecular electronics.In this paper,tetra-p-(3-mercaptopropyloxy)-phenyl]porphyrin was synthesized and self-assembled with thiol on Au substrate for porphyrin SAMs(PPS 4).The electrochemical results demonstrated that PPS 4 could form excellent SAMs on gold surface.Self-assembled nanojunctions of PPS 4 were fabricated by using gold nanogap electrodes(gap width:ca.100 nm).With the light on/off,the nanojunctions showed current high/low as nanometer scaled photo switch.