Albumin Analysis by Potentiometric Method

Procedure

Cleaning of Al2O3 substrate

Acetone ultrasonification for 5 mins

Ethanol ultrasonification for 5 mins

Deionizied water ultrasonification for

3 mins

Drying in oven

Preparation of Au electrode

Imprinting Au gel on substrate by halftone

Annealing Au thick film by programming

Etching by 1.00 N NaOH and HCl solutions for 10 mins, respectively,then, washing by H2O thoroughly

Drying Au electrode by N2 gas at room

temperature

Modification of Au electrode

Preparation of 1.00 mM thiol ethanol/ water

(4/1 v/v ) solution

Modification of Au electrode in thiol solution 12 hrs at least

under room temperature

Washing electrode by deionizied water and ethanol thoroughly

Drying modified electrode by N2 at room temperature

Preparation of Au MIP sensing film

Spin-coating albumin containing reactive

solution on Au electrode

Photo-polymerization by 365 nm UV lightening for

36 hrs under N2 circumstance

Washing out albumin molecule by 20 wt % methanol aqueous

solution and detected by UV/Vis

No albumin was detectedin the eluted solution by

the UV/Vis

Experimental Sequence of Potentiometric Method

Preparation of electrode Stabilization of electrode

potential in open circuit

Determine V of electrode

after albumin additionLinear regression of V

and albumin concn.