Biosensors for the detection of proteins and bacteria have been developed using glycopolymer-immobilized metal mesh devices. The trimethoxysilane-containing glycopolymer was immobilized onto a metal mesh device using the silane coupling reaction. The surface shape and transmittance properties of the original metal mesh device were maintained following the immobilization of the glycopolymer. The mannose-binding protein (concanavalin A) could be detected at concentrations in the range of 10(-9) to 10(-6) mol L(-1) using the glycopolymer-immobilized metal mesh device sensor, whereas another protein (bovine serum albumin) was not detected. A detection limit of 1 ng mm(-2) was achieved for the amount of adsorbed concanavalin A. The glycopolymer-immobilized metal mesh device sensor could also detect bacteria as well as protein. The mannose-binding strain of Escherichia coli was specifically detected by the glycopolymer-immobilized metal mesh device sensor. The glycopolymer-immobilized metal mesh device could therefore be used as a label-free biosensor showing high levels of selectivity and sensitivity toward proteins and bacteria.