Polymers Doped with Carbon Nanoparticles As Hot Electron Emission Materials for HECL Bioaffinity Assays

Abstract

This contribution presents simple methods to fabricate hot electron-emitting composite electrodes. Hot electron-induced electrochemiluminescence (HECL) typically utilizes luminophores as labels in sensitive bioaffinity assays, where the electrodes can inject hot electrons into aqueous electrolyte solutions, possessing more energy than that of conduction band edge of water and hence generate hydrated electrons as a mediating species and HECL for detection of labels utilized. In this study, the hot electron emitting composite electrodes fabricated by doping polymer materials with few different types carbon particles and coating metal substrates with the above-mentioned composite layers with different carbon-polymer mass fractions. An aromatic Tb(III) chelate was used as a probe, that is known not to be excited on the basis of traditional electrochemistry but to be efficiently electrically excited in the presence of hydrated electrons, and during injection of hot electrons into aqueous solution. Thus, the presence of hot, prehydrated or hydrated electrons at the close vicinity of the composite electrode surface were monitored by electrogenerated chemiluminescence. These inexpensive and easily fabricated composite electrode materials can be used in HECL bioaffinity assays and other applications of hot electron electrochemistry. Finally, it is shown that the present types composite electrodes can be fabricated by printing and used in real-world immunoanalysis of human C-reactive protein.