Carboxy-terminated thiols are truly versatile and have been used in applications ranging from soft lithography (Dubois, L.H et al. J. Am. Chem. Soc., 1990, 112, 570; Laibinis, P.E. et al. J. Phys. Chem. , 1995, 99, 7663), through immobilization of biomolecules (Chen, S. et al. Langmuir, 2003, 19, 2859) and molecular electronics (Rampi, M.A.; Whitesides, G.M. Chem. Phys. , 2002, 281, 373) to electrochemical detection (alone or in combination with ferrocenyl thiols; Zhao, J.W. et al. Electroanal., 1999, 11, 1108) and electrostatic self-assembly (Tien, J. et al. Langmuir, 1997, 13, 5349). The thiol we sell is of very high purity and has a minimal content of corresponding disulfide that could adversely influence the tight- packing of the SAM.