Albumin Analysis by Potentiometric Method

Fig 1. 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)

situationNo.1 0ppmNo.1 3ppm 5min.No.1 after wash 1hrwash again 2hr

situationEpa Epc Ipa Ipc

(V vs. Ag/AgCl(0.5MKCl)) (A)

0 ppm 0.251 0.141 68.60 -65.05

3 ppm albumin (Dipping for

5min)0.269 0.118 59.83 -53.10

Wash by 6M urea (Dipping

for 1hr)0.313 0.075 37.12 -33.06

Wash again by 6M urea

(Dipping for 2hr)0.391 0.040 33.63 -36.18

Table : The effect of 6M urea solution on the peak current

Fig 6. 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 10minfirst washsecond 3ppm 3minsecond washthird 3ppm 1hr

Table Ⅴ: The peak current reproduciblity of electrodetreated by traditional method

situationEpa Epc Ipa Ipc

(V vs. Ag/AgCl(0.5MKCl)) (A)

0 ppm 0.258 0.135 65.84 -64.94

First 3 ppm albumin(dipping

for 10min)0.260 0.128 63.78 -54.03

First wash 0.285 0.122 53.14 -59.71

second 3 ppm albumin(dipping

for 3min)0.272 0.110 55.15 -47.61

second wash 0.282 0.132 54.25 -55.33

third 3 ppm albumin(dipping

for 1hr)0.294 0.096 43.41 -40.37