Abstract: An electrochemical sensor is provided containing a supporting material having a surface of noble metal such as gold or palladium to which is bound an enzyme such as glucose oxidase via binding molecules. The binding molecules are in the form of a homogenous monolayer and are bound to the metal surface by anchor groups such as thiol, disulphide or phosphine groups. The enzyme is linked to the binding molecules by an ionic bond, a covalent bond or a metal-chelate bond. The binding molecules may contain a spacer such as an alkylene chain. Coverage of the binding molecules on the metal surface is less than the maximum coverage to optimize enzyme coverage, decrease response time of the sensor and increase signal yield per surface area. The monolayer may contain diluent molecules which are not linked to an enzyme and which are bound to the metal surface via anchor groups.

Abstract: The present invention provides compounds of the general formula: ##STR1## wherein R.sub.1 is a straight-chained or branched C.sub.1 -C.sub.12 -alkyl radical which can be substituted by phenyl, naphthyl or a C.sub.3 -C.sub.7 -cycloalkyl radical; a straight-chained or branched C.sub.2 -C.sub.6 -alkenyl radical which can be substituted by a C.sub.3 -C.sub.7 -cycloalkyl radical or a phenyl or naphthyl radical; a C.sub.3 -C.sub.7 -cycloalkyl radical or a mono- or bicyclic aromatic radical which is unsubstituted or substituted one or more times, the substituents being C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, carboxyl or carbethoxy, R.sub.2 and R.sub.3, which can be the same or different, are straight-chained or branched, saturated or unsaturated C.sub.1 -C.sub.6 -alkyl radicals which are optionally substituted by hydroxyl, C.sub.1 -C.sub.3 -alkoxy or C.sub.1 -C.sub.3 -alkoxy-C.sub.1 -C.sub.