Modified Gold Substrate Research Articles

Selective adsorption of oligonucleotides on switchable self-assembled monolayers

Short oligonucleotides adsorb rapidly and selectively on pH-switchable self-assembled layers of bisbenzamidines on modified gold substrates.

Self-Assembly of Monolayers of Semiconductor Nanocrystallites

Described is the self-assembly of a monolayer of TiO2 nanocrystallites on a gold substrate by two related methods. In the first of these methods, a crystalline monolayer of the functionalized thiol HS−(CH2)10−COOH is self-assembled at an annealed gold substrate by adsorption from ethanolic solution. The modified gold substrate is then immersed in an ethanolic TiO2 colloid. TiO2 nanocrystallites are adsorbed at the terminal −COOH group of the molecules constituting the monolayer. In the second of these methods, an ethanolic colloid of TiO2 nanocrystallites is prepared in the presence of the functionalized thiol HS−(CH2)10−COOH. The modified nanocrystallites are adsorbed at the surface of an annealed gold substrate. For each method, there is some evidence for short-range ordering of the nanocrystallites constituting the close-packed monolayer adsorbed at the gold substrate. Some potential applications of these methods are considered.

The giant Raman Effect from pyridine on a chemically modified gold substrate

Enhanced Raman scattering from adsorbed pyridine has been observed with 5145 nm incident radiation on a slightly rough Au substrate onto which electrochemically controlled monolayer quantities of Ag have been deposited. This result supports enhancement models in which specific chemistry between the adsorbate and the substrate is important.