TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The semiconductor nanoparticles are cadmium sulfide, cadmium selenide, cadmium telluride, and/or indium selenide. The noble metal nanoparticles are ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and/or gold. The ratio of semiconductor nanoparticles to noble metal nanoparticles in matrix is 0.1-10.0. The electron acceptor group of the electrode is ferric cyanide and/or molybdenum cyanide. Preferred Parameters: The transfer of electrons mediated by matrix connecting group and/or surface connecting group is achieved through charge-hopping or electron tunneling. Preferred Composition: The electrode comprises at least one electron acceptor group having redox potential that is more positive than the conductive band of the semiconductor nanoparticles.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The electropolymerized monomer is thioaniline, thiophenol, amino-thiophenol, and/or thiopyrrole. The electron acceptor group of the electrode is N,N'-dimethyl-4,4'-bipyridinium and/or quinone.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The matrix connecting group is an electropolymerized oligomer. The electropolymerized oligomer comprises at least two anchoring groups which may be the same or different and are each independently chemically associated with at least one nanoparticle of the matrix; and optionally substituted aromatic or heteroaromatic moieties. The surface connecting group is electropolymerized oligomer. The matrix connecting group is a group of formula Z1-L1-Z2. The surface connecting group is of formula Z3-L2-Z4. The electropolymerized oligomer comprises at least 2 anchoring groups which may be the same or different and are each independently chemically associated with at least one nanoparticle of the matrix and/or conductive surface. The electropolymerized oligomer comprises one or more optionally substituted aromatic or heteroaromatic moieties.Z1, Z2=bond or moiety independently chemically associated with at least one nanoparticle;L1=linker group comprising at least one electropolymerized monomer or oligomer, preferably optionally substituted aromatic or heteroaromatic moieties;Z3, Z4=bond or a moiety that are each independently chemically associated with at least one nanoparticle or conductive surface; andL2=linker group comprising at least one electropolymerized monomer or oligomer, preferably optionally substituted aromatic or heteroaromatic moieties.