Dr. Chamras Promptmas graduated first degree in Medical Technology, Mahidol University in 1976. He received his M.Sc. degree in Biochemistry from Chulalongkorn University in 1980 and diploma in biotechnology from the University of Kent at Canterbury, UK, in 1988. He completed his Ph.D. degree in biochemistry from Mahidol University under the supervision of Associate Professor Dr. Bhinyo Panichpan in 1994. After the completion of THAI-USAID Workshop on Biosensor Technology in 1994 and also Biosensor Development Training in Institute of Chemical and Biosensor Research, Muenster, in 1998, The Biosensor Research Laboratory was established in Faculty of Medical Technology, Mahidol University. The experience in Biosensor field has been incorporated into the research interest in Development of Biosensor Technology for Laboratory Diagnostics applications using several biosensor platforms such as electrochemical, quartz crystal microbalance, microcantilever and optical device. He was also appointed as head of Clinical Chemistry Department for 15 years. In 2015, He joined the department of Biomedical Engineering, Faculty of Engineering, Mahidol University as the Director of Biosensors and Micro Total Analysis System Laboratory. He continued his research on biosensors and expanded to the application of Ion Sensitive Field Effect Transistor (ISFET) and microfluidic systems. Supervisors: Dr. Bhinyo Panichpan
We presented a cost-effective design of electrochemical based biosensor for non-enzymatic glucose... more We presented a cost-effective design of electrochemical based biosensor for non-enzymatic glucose detection in urine. By incorporating low-cost, non-precious cobalt (Co)/iron (Fe) metals, the sensor was employed onto the three-electrode system for quantifying glucose level from 0 to 3.25 mM in artificial urine medium and clinical simulated urine solution, namely, Surine. In particular, the fabricated CoFe nanoparticles on N-doped graphene (NG) biosensor was assessed electrochemical performances by cyclic voltammetry and amperometry at applied potential of +0.90 V versus Ag/AgCl, in comparison with that of CoFe on carbon supported. Based on the results, it was found that two processes of catalytic oxidation and oxide depletion are involved in glucose detection. More importantly, the as-prepared biosensor exhibited an outstanding sensitivity of 476.67 µA.cm−2.mM−1 with R2 of 0.9974 in Surine. Furthermore, the low limit of detection was estimated to be 37.7 µM (signal-to-noise ratio of 3) with an excellent anti-interference property toward ascorbic acid, uric acid, and chlorine ions, providing a promising advancement for future glucose measurement in urine, applicable for sustainable diabetic prognosis and management.
We have previously developed quartz crystal microbalance biosensor integrated with loop-mediated ... more We have previously developed quartz crystal microbalance biosensor integrated with loop-mediated isothermal amplification (LAMP-QCM) for human papillomavirus (HPV) type58 DNA detection. Infection with HPV, particularly HPV16, remains a serious health problem due to its major risk factor contributing to cervical cancer. In the present study, LAMP-QCM biosensor was evaluated in terms of a quantitative assay for copy number of HPV16 DNA in cervical samples compared to quantitative PCR using TaqMan assay (TaqMan-qPCR). The detection limit of LAMP-QCM was found to be 10 fold more sensitive than TaqMan-qPCR with 100% specificity and 7.6% imprecision. Different plot of HPV16 DNA copy number using Bland-Altman analysis revealed 94% correlation between LAMP-QCM and qPCR. We therefore concluded that the developed LAMP-QCM biosensor provides a possible rapid and sensitive assay for HPV16 DNA quantification in a routine laboratory.
Abstract Development of non-invasive glucose measurement allows future advancement of smart sensi... more Abstract Development of non-invasive glucose measurement allows future advancement of smart sensing platform for diagnostic technology. Especially for endocrine disorders, advanced kidney diseases, and diabetes, monitoring excessive glucose level in urine can provide invaluable information for clinical prognosis and preventive healthcare. Herein, we present a comparative electrochemical study of cobalt/iron (CoFe) catalyst on nitrogen-doped graphene (NG) for non-enzymatic glucose detection, carried out in physiological pH urine including (i) modified artificial urine medium (mAUM), (ii) commercial standard urine (Surine), and (iii) human urine specimens. With no requirement of strong alkaline addition, catalytic properties of CoFe-NG were assessed by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on a glassy carbon rotating disk electrode. Upon successive glucose additions from 0 to 3 mM, DPV results revealed two anodic peaks at +0.18 V and +0.42 V versus Ag/AgCl, corresponding to Co3+ and Co4+ as a result of glucose binding in urine. By evaluating at +0.18 V, the sensitivities of CoFe-NG were estimated to be 16.77 (R2 = 0.987), 45.36 (R2 = 0.988), and 20.26 (R2 = 0.991) μA mM−1 cm−2 with the limit of detection of 0.25, 0.07, and 0.19 mM in mAUM, Surine, and human urine specimen with low serum creatinine, respectively. Furthermore, the effects of CoFe on graphene (G) and carbon Vulcan XC-72 (C) were also studied in comparison of NG on the bimetal. Interestingly, CoFe-C showed a good electrochemical trend in glucose detection in urine. However, negligible catalytic activity was presented in CoFe-G. Thus, electrochemical responses of CoFe-C were also further studied in the comparison of CoFe-NG in each type of urine. Overall, CoFe-NG outperformed CoFe-C in all types of urine and exhibited an excellent anti-interference property toward uric acid, thereby suggesting great potential for the next generation of glucose sensing platform in urine.
Forkhead box protein M1 (FOXM1) is a proliferation-associated transcription factor contributing t... more Forkhead box protein M1 (FOXM1) is a proliferation-associated transcription factor contributing to the G2/M phase transition of the cell cycle. Although the upregulation of FOXM1 has been observed in different cancer types, how the regulation of FOXM1 dynamically alters during cell cycles and potentially contributes to tumorigenesis is not well understood. We showed here the development and application of a tunable FOXM1-DHFR (FOXM1-D) sensor that enables surveillance and manipulation of the FOXM1 abundance. Using trimethoprim (TMP) to stabilize the sensor, we measured the kinetics of FOXM1-D production, degradation, and cytosolic-to-nuclear translocation in the G1 and G2 cell-cycle phases. By controlling FOXM1-D stability in different synchronized cell cycle pools, we found that the G1- and S-synchronized cells finished their first cell division faster, although the G2-synchronized cells were unaffected. Our analysis of single-cell FOXM1-D dynamics revealed that the two-round divid...
The objective of this research work is to propose a phase diagram that can be used to find a prop... more The objective of this research work is to propose a phase diagram that can be used to find a proper operating condition for generating droplets of different types. It is found that the phase diagram of QR versus CaD can effectively classify the droplet generation into three vivid regimes: dripping, jetting and tubing. For the dripping regime, its operating condition is in the range of either CaD < 10−4 and QR < 50 or 10−3 < CaD < 10−4 and QR < 1. For the jetting regime, its operating condition is in the range of either CaD < 1.35 × 10−2 and QR > 100 or CaD > 1.35 × 10−2 and QR > 1. For the tubing regime, its operating condition is in the range of CaD > 1.35 × 10−2 and QR < 1.
This work demonstrates the ability of the Ion-Sensitive Field-Effect Transistor (ISFET)-based imm... more This work demonstrates the ability of the Ion-Sensitive Field-Effect Transistor (ISFET)-based immunosensor to detect antibodies against the human leukocyte antigen (HLA) and the major histocompatibility complex class-I-related chain A (MICA). The sensing membrane of the ISFET devices was modified and functionalized using an APTES-GA strategy. Surface properties, including wettability, surface thickness, and surface topology, were assessed in each module of the modification process. The optimal concentrations of HLA and MICA proteins for the immobilization were 10 and 50 μg/mL. The dose-response curve showed a detection range of 1.98–40 µg/mL for anti-HLA and 5.17–40 µg/mL for anti-MICA. The analytical precision (%CV) was found to be 10.69% and 8.92% for anti-HLA and -MICA, respectively. Moreover, the electrical signal obtained from the irrelevant antibody was considerably different from that of the specific antibodies, indicating the specific binding of the relevant antibodies witho...
Electron transfer flavoprotein subunit beta (ETFB) of Leptospira interrogans is a biomarker for d... more Electron transfer flavoprotein subunit beta (ETFB) of Leptospira interrogans is a biomarker for diagnosing leptospiral infection.
An essential biomarker for the early detection of cardiovascular diseases is serum homocysteine (... more An essential biomarker for the early detection of cardiovascular diseases is serum homocysteine (Hcy). In this study, a molecularly imprinted polymer (MIP) and nanocomposite were used to create a label-free electrochemical biosensor for reliable Hcy detection. A novel Hcy-specific MIP (Hcy-MIP) was synthesized using methacrylic acid (MAA) in the presence of trimethylolpropane trimethacrylate (TRIM). The Hcy-MIP biosensor was fabricated by overlaying the mixture of Hcy-MIP and the carbon nanotube/chitosan/ionic liquid compound (CNT/CS/IL) nanocomposite on the surface of a screen-printed carbon electrode (SPCE). It showed high sensitivity, with a linear response of 5.0 to 150 µM (R2 of 0.9753) and with a limit of detection (LOD) at 1.2 µM. It demonstrated low cross-reactivity with ascorbic acid, cysteine, and methionine. Recoveries of 91.10–95.83% were achieved when the Hcy-MIP biosensor was used for Hcy at 50–150 µM concentrations. The repeatability and reproducibility of the biosens...
We presented a cost-effective design of electrochemical based biosensor for non-enzymatic glucose... more We presented a cost-effective design of electrochemical based biosensor for non-enzymatic glucose detection in urine. By incorporating low-cost, non-precious cobalt (Co)/iron (Fe) metals, the sensor was employed onto the three-electrode system for quantifying glucose level from 0 to 3.25 mM in artificial urine medium and clinical simulated urine solution, namely, Surine. In particular, the fabricated CoFe nanoparticles on N-doped graphene (NG) biosensor was assessed electrochemical performances by cyclic voltammetry and amperometry at applied potential of +0.90 V versus Ag/AgCl, in comparison with that of CoFe on carbon supported. Based on the results, it was found that two processes of catalytic oxidation and oxide depletion are involved in glucose detection. More importantly, the as-prepared biosensor exhibited an outstanding sensitivity of 476.67 µA.cm−2.mM−1 with R2 of 0.9974 in Surine. Furthermore, the low limit of detection was estimated to be 37.7 µM (signal-to-noise ratio of 3) with an excellent anti-interference property toward ascorbic acid, uric acid, and chlorine ions, providing a promising advancement for future glucose measurement in urine, applicable for sustainable diabetic prognosis and management.
We have previously developed quartz crystal microbalance biosensor integrated with loop-mediated ... more We have previously developed quartz crystal microbalance biosensor integrated with loop-mediated isothermal amplification (LAMP-QCM) for human papillomavirus (HPV) type58 DNA detection. Infection with HPV, particularly HPV16, remains a serious health problem due to its major risk factor contributing to cervical cancer. In the present study, LAMP-QCM biosensor was evaluated in terms of a quantitative assay for copy number of HPV16 DNA in cervical samples compared to quantitative PCR using TaqMan assay (TaqMan-qPCR). The detection limit of LAMP-QCM was found to be 10 fold more sensitive than TaqMan-qPCR with 100% specificity and 7.6% imprecision. Different plot of HPV16 DNA copy number using Bland-Altman analysis revealed 94% correlation between LAMP-QCM and qPCR. We therefore concluded that the developed LAMP-QCM biosensor provides a possible rapid and sensitive assay for HPV16 DNA quantification in a routine laboratory.
Abstract Development of non-invasive glucose measurement allows future advancement of smart sensi... more Abstract Development of non-invasive glucose measurement allows future advancement of smart sensing platform for diagnostic technology. Especially for endocrine disorders, advanced kidney diseases, and diabetes, monitoring excessive glucose level in urine can provide invaluable information for clinical prognosis and preventive healthcare. Herein, we present a comparative electrochemical study of cobalt/iron (CoFe) catalyst on nitrogen-doped graphene (NG) for non-enzymatic glucose detection, carried out in physiological pH urine including (i) modified artificial urine medium (mAUM), (ii) commercial standard urine (Surine), and (iii) human urine specimens. With no requirement of strong alkaline addition, catalytic properties of CoFe-NG were assessed by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on a glassy carbon rotating disk electrode. Upon successive glucose additions from 0 to 3 mM, DPV results revealed two anodic peaks at +0.18 V and +0.42 V versus Ag/AgCl, corresponding to Co3+ and Co4+ as a result of glucose binding in urine. By evaluating at +0.18 V, the sensitivities of CoFe-NG were estimated to be 16.77 (R2 = 0.987), 45.36 (R2 = 0.988), and 20.26 (R2 = 0.991) μA mM−1 cm−2 with the limit of detection of 0.25, 0.07, and 0.19 mM in mAUM, Surine, and human urine specimen with low serum creatinine, respectively. Furthermore, the effects of CoFe on graphene (G) and carbon Vulcan XC-72 (C) were also studied in comparison of NG on the bimetal. Interestingly, CoFe-C showed a good electrochemical trend in glucose detection in urine. However, negligible catalytic activity was presented in CoFe-G. Thus, electrochemical responses of CoFe-C were also further studied in the comparison of CoFe-NG in each type of urine. Overall, CoFe-NG outperformed CoFe-C in all types of urine and exhibited an excellent anti-interference property toward uric acid, thereby suggesting great potential for the next generation of glucose sensing platform in urine.
Forkhead box protein M1 (FOXM1) is a proliferation-associated transcription factor contributing t... more Forkhead box protein M1 (FOXM1) is a proliferation-associated transcription factor contributing to the G2/M phase transition of the cell cycle. Although the upregulation of FOXM1 has been observed in different cancer types, how the regulation of FOXM1 dynamically alters during cell cycles and potentially contributes to tumorigenesis is not well understood. We showed here the development and application of a tunable FOXM1-DHFR (FOXM1-D) sensor that enables surveillance and manipulation of the FOXM1 abundance. Using trimethoprim (TMP) to stabilize the sensor, we measured the kinetics of FOXM1-D production, degradation, and cytosolic-to-nuclear translocation in the G1 and G2 cell-cycle phases. By controlling FOXM1-D stability in different synchronized cell cycle pools, we found that the G1- and S-synchronized cells finished their first cell division faster, although the G2-synchronized cells were unaffected. Our analysis of single-cell FOXM1-D dynamics revealed that the two-round divid...
The objective of this research work is to propose a phase diagram that can be used to find a prop... more The objective of this research work is to propose a phase diagram that can be used to find a proper operating condition for generating droplets of different types. It is found that the phase diagram of QR versus CaD can effectively classify the droplet generation into three vivid regimes: dripping, jetting and tubing. For the dripping regime, its operating condition is in the range of either CaD < 10−4 and QR < 50 or 10−3 < CaD < 10−4 and QR < 1. For the jetting regime, its operating condition is in the range of either CaD < 1.35 × 10−2 and QR > 100 or CaD > 1.35 × 10−2 and QR > 1. For the tubing regime, its operating condition is in the range of CaD > 1.35 × 10−2 and QR < 1.
This work demonstrates the ability of the Ion-Sensitive Field-Effect Transistor (ISFET)-based imm... more This work demonstrates the ability of the Ion-Sensitive Field-Effect Transistor (ISFET)-based immunosensor to detect antibodies against the human leukocyte antigen (HLA) and the major histocompatibility complex class-I-related chain A (MICA). The sensing membrane of the ISFET devices was modified and functionalized using an APTES-GA strategy. Surface properties, including wettability, surface thickness, and surface topology, were assessed in each module of the modification process. The optimal concentrations of HLA and MICA proteins for the immobilization were 10 and 50 μg/mL. The dose-response curve showed a detection range of 1.98–40 µg/mL for anti-HLA and 5.17–40 µg/mL for anti-MICA. The analytical precision (%CV) was found to be 10.69% and 8.92% for anti-HLA and -MICA, respectively. Moreover, the electrical signal obtained from the irrelevant antibody was considerably different from that of the specific antibodies, indicating the specific binding of the relevant antibodies witho...
Electron transfer flavoprotein subunit beta (ETFB) of Leptospira interrogans is a biomarker for d... more Electron transfer flavoprotein subunit beta (ETFB) of Leptospira interrogans is a biomarker for diagnosing leptospiral infection.
An essential biomarker for the early detection of cardiovascular diseases is serum homocysteine (... more An essential biomarker for the early detection of cardiovascular diseases is serum homocysteine (Hcy). In this study, a molecularly imprinted polymer (MIP) and nanocomposite were used to create a label-free electrochemical biosensor for reliable Hcy detection. A novel Hcy-specific MIP (Hcy-MIP) was synthesized using methacrylic acid (MAA) in the presence of trimethylolpropane trimethacrylate (TRIM). The Hcy-MIP biosensor was fabricated by overlaying the mixture of Hcy-MIP and the carbon nanotube/chitosan/ionic liquid compound (CNT/CS/IL) nanocomposite on the surface of a screen-printed carbon electrode (SPCE). It showed high sensitivity, with a linear response of 5.0 to 150 µM (R2 of 0.9753) and with a limit of detection (LOD) at 1.2 µM. It demonstrated low cross-reactivity with ascorbic acid, cysteine, and methionine. Recoveries of 91.10–95.83% were achieved when the Hcy-MIP biosensor was used for Hcy at 50–150 µM concentrations. The repeatability and reproducibility of the biosens...
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