Galvanic Displacement of Nanostructured Gold for Flavoenzyme Adsorption in Biotechnology

Abstract

Sensors are the devices which are composed of an active sensing material with a signal transducer. The recent development in the nanotechnology has paved the way for large number of new materials and devices of desirable properties which have useful functions for numerous electrochemical sensor and biosensor applications. In this work, results on the galvanic displacement of gold on silicon in different electrolytes will be presented. The growth of the gold films is characterized and the interfacial behavior with the substrate is characterized by microindentation in order to highlight the adhesion as a function of the electrolyte. Results on high surface area gold nanostructures on silicon will be presented. Such films will be tested and surface morphology will be correlated to the adsorption of flavoenzymes.

Structural, Mechanical and Electrical Characteristics of Copper Coatings Obtained by Various Electrodeposition Processes

“…The adhesion parameter, b was calculated from slope of the linear dependencies shown in this Figure , and the calculated values are given in the Table 3. The larger value of the adhesion parameter b means the better adhesion of the coating with substrate [23][24][25][26][30][31][32]. From Table 3, it can be seen that the Cu coatings obtained at 33 and 67 mA cm −2 with ultrasound stirring of the electrolyte showed better adhesion than those obtained without the electrolyte stirring.…”

“…Equation ( 2) was used to calculate the critical reduced depth, b, parameter representing an estimation of adhesion of any coating with substrate [23][24][25][26][30][31][32]. The value of the parameter n in Equation ( 2) is either 1.2 or 1.8, and for "soft coatings on hard substrate" like the Cu coatings on the brass substrate analyzed here, the value n of 1.8 was taken [26,30].…”

“…Equation ( 2) was used to calculate the critical reduced depth, b, parameter representing an estimation of adhesion of any coating with substrate [23][24][25][26][30][31][32]. The value of the parameter n in Equation ( 2) is either 1.2 or 1.8, and for "soft coatings on hard substrate" like the Cu coatings on the brass substrate analyzed here, the value n of 1.8 was taken [26,30]. In this calculation, the value of hardness of the brass substrate (Hs) of 1.41 GPa [5] was taken, while the values of the absolute hardness calculated according to C-G model (Table 2) were taken for a determination of ΔH in the Equation ( 2).…”

“…Another important mechanical property of interest for the development of microstructure components is the adhesion between layers, i.e., between coating and substrate (cathode). In this paper, the assessment of adhesion between copper coating and substrate was done on the basis of a composite hardness model Chen-Gao and a change in the value of the critical reduced depth (adhesion parameter, b) [23][24][25][26]28,[30][31][32]. The basis of the theory of the composite hardness model according to Chen-Gao (C-G) is given in Appendix A.…”