Albumin Analysis by Potentiometric Method

#2 Process of preparing Au wire electrode

Polish the electrode surface by polishing paper (1500 mesh)

Seal the electrode by epoxy adhesive excepts the sensing area(wait for a night)

Clean the electrode by ultrasonic for 3 min.

wipe by delicate task wiper

Dip into 1N NaOH(aq)for 10min.

Dry by N2(g)

Wash by DI water for several times

Dip into 1N HCl(aq)for 10min.

Wash by DI water for several times

Dry by N2(g)

Dip into 1N HNO3(aq)for 10min.

Wash by DI water for several times

Dry by N2(g)

#2 Process of preparing Au wire electrode

Scan C-V (0ppm)

Dry by N2(g)

Dip in 10ml DI water for 20sec. for five times

Dip into 0.1ml albumin(aq/0.5M KCl for a setting period.

Wash by DI water for several times

#2 Process of preparing Au wire electrode

Scan C-V

Dry by N2(g)

Dry by N2(g)

Dip into 10ml DI water for 20sec. for five times

Dip into 1N NaOH(aq)for 10min.

Dry by N2(g)

Wash by DI water for several times

Dip into 1N HCl(aq)for 10min.

Wash by DI water for several times

#2 Process of preparing Au wire electrode

Dry by N2(g)

Dip into 1N HNO3(aq)for 10min.

Wash by DI water for several times

Dry by N2(g)

Scan C-V

Fig 5. The cyclic voltammogram of Au wire electrode

WE: Au wire, WE area: 0.0113 cm2, RE: Ag/AgCl(0.5M), CE: Pt, Electrolyte: 0.5 M KCl 50 ml(20 mM K4Fe(CN)6+20 mM K3Fe(CN)6), Potentiostat: CHI-405, Scan range: -0.2~0.6 V, scan rate: 0.05 V/sec

-0.2 0 0.2 0.4 0.6Potential (V vs.Ag/AgCl(0.5MKCl))

- 8 0

- 4 0

0

4 0

8 0

Cu

rren

t (

A)

situation0ppmfirst 3ppm 5m infirst washsecond 3ppm 1minsecond washthird 3ppm 30min