Abstract
This study attempted to determine absolute heparin concentration in phosphate buffer solution (PBS, pH 7.4) by using quartz crystal microbalance (QCM) as an affinity biosensor. Electrochemical impedance spectroscopy (EIS) was also used to investigate immobilization of protamine and heparin assay. In addition, the effectiveness of physical adsorption in immobilizing protamine was confirmed by examining the preparation conditions, including the incubation time and protamine concentration. It induced maximum decrease (ca. -100Hz) in oscillating frequency of QCM by applying 20mg/ml protamine and 20min for incubation in PBS. Heparin adsorption onto protamine-modified electrode in PBS revealed an exponential-like binding curve and long duration for reaching the steady state in frequency response of QCM. Moreover, two linear calibration curves were obtained judging from the initial slope (df/dt) and the frequency change (Δf) of QCM obtained after a binding interval (600s) for heparin concentrations from 0 to 3.0 and 7.0U/ml, respectively. In EIS analysis, calibration curves with linear concentration range of 0-3.0U/ml were obtained for heparin in PBS when ferrocyanide was used as an electroactive marker.
| Original language | English |
|---|---|
| Pages (from-to) | 261-273 |
| Number of pages | 13 |
| Journal | Analytica Chimica Acta |
| Volume | 462 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2002 Jul 1 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Environmental Chemistry
- Biochemistry
- Spectroscopy
Cite this
}
Physical adsorption of protamine for heparin assay using a quartz crystal microbalance and electrochemical impedance spectroscopy. / Cheng, Tzong Jih; Lin, Tsun Mei; Chang, Hsien-Chang.
In: Analytica Chimica Acta, Vol. 462, No. 2, 01.07.2002, p. 261-273.Research output: Contribution to journal › Article
TY - JOUR
T1 - Physical adsorption of protamine for heparin assay using a quartz crystal microbalance and electrochemical impedance spectroscopy
AU - Cheng, Tzong Jih
AU - Lin, Tsun Mei
AU - Chang, Hsien-Chang
PY - 2002/7/1
Y1 - 2002/7/1
N2 - This study attempted to determine absolute heparin concentration in phosphate buffer solution (PBS, pH 7.4) by using quartz crystal microbalance (QCM) as an affinity biosensor. Electrochemical impedance spectroscopy (EIS) was also used to investigate immobilization of protamine and heparin assay. In addition, the effectiveness of physical adsorption in immobilizing protamine was confirmed by examining the preparation conditions, including the incubation time and protamine concentration. It induced maximum decrease (ca. -100Hz) in oscillating frequency of QCM by applying 20mg/ml protamine and 20min for incubation in PBS. Heparin adsorption onto protamine-modified electrode in PBS revealed an exponential-like binding curve and long duration for reaching the steady state in frequency response of QCM. Moreover, two linear calibration curves were obtained judging from the initial slope (df/dt) and the frequency change (Δf) of QCM obtained after a binding interval (600s) for heparin concentrations from 0 to 3.0 and 7.0U/ml, respectively. In EIS analysis, calibration curves with linear concentration range of 0-3.0U/ml were obtained for heparin in PBS when ferrocyanide was used as an electroactive marker.
AB - This study attempted to determine absolute heparin concentration in phosphate buffer solution (PBS, pH 7.4) by using quartz crystal microbalance (QCM) as an affinity biosensor. Electrochemical impedance spectroscopy (EIS) was also used to investigate immobilization of protamine and heparin assay. In addition, the effectiveness of physical adsorption in immobilizing protamine was confirmed by examining the preparation conditions, including the incubation time and protamine concentration. It induced maximum decrease (ca. -100Hz) in oscillating frequency of QCM by applying 20mg/ml protamine and 20min for incubation in PBS. Heparin adsorption onto protamine-modified electrode in PBS revealed an exponential-like binding curve and long duration for reaching the steady state in frequency response of QCM. Moreover, two linear calibration curves were obtained judging from the initial slope (df/dt) and the frequency change (Δf) of QCM obtained after a binding interval (600s) for heparin concentrations from 0 to 3.0 and 7.0U/ml, respectively. In EIS analysis, calibration curves with linear concentration range of 0-3.0U/ml were obtained for heparin in PBS when ferrocyanide was used as an electroactive marker.
UR - http://www.scopus.com/inward/record.url?scp=0036644533&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036644533&partnerID=8YFLogxK
U2 - 10.1016/S0003-2670(02)00335-5
DO - 10.1016/S0003-2670(02)00335-5
M3 - Article
AN - SCOPUS:0036644533
VL - 462
SP - 261
EP - 273
JO - Analytica Chimica Acta
JF - Analytica Chimica Acta
SN - 0003-2670
IS - 2
ER -