title: Electrochemical detection of high-sensitivity CRP inside a microfluidic device by numerical and experimental studies.
abstract: The concentration of C-reactive protein (CRP), a classic acute phase plasma protein, increases rapidly in response to tissue infection or inflammation, especially in cases of cardiovascular disease and stroke. Thus, highly sensitive monitoring of the CRP concentration plays a pivotal role in detecting these diseases. Many researchers have studied methods for the detection of CRP concentrations such as optical, mechanical, and electrochemical techniques inside microfluidic devices. While significant progress has been made towards improving the resolution and sensitivity of detection, only a few studies have systematically analyzed the CRP concentration using both numerical and experimental approaches. Specifically, systematic analyses of the electrochemical detection of high-sensitivity CRP (hsCRP) using an enzyme-linked immunosorbant assay (ELISA) inside a microfluidic device have never been conducted. In this paper, we systematically analyzed the electrochemical detection of CRP modified through the attachment of an alkaline phosphatase (ALP-labeled CRP) using ELISA inside a chip. For this analysis, we developed a model based on antigen-antibody binding kinetics theory for the numerical quantification of the CRP concentration. We also experimentally measured the current value corresponding to the ALP-labeled CRP concentration inside the microfluidic chip. The measured value closely matched the calculated value obtained by numerical simulation using the developed model. Through this comparison, we validated the numerical simulation methods, and the calculated and measured values. Lastly, we examined the effects of various microfluidic parameters on electrochemical detection of the ALP-labeled CRP concentration using numerical simulations. The results of these simulations provide insight into the microfluidic electrochemical reactions used for protein detection. Furthermore, the results described in this study should be useful for the design and optimization of electrochemical immunoassay chips for the detection of target proteins.
authors.affiliation: Department of Biomedical Engineering, Yonsei University, Wonju, Kangwon 220-710, Republic of Korea.
authors.forename: Gyudo
authors.initials: G
authors.lastname: Lee
authors.forename: Insu
authors.initials: I
authors.lastname: Park
authors.forename: Kiwoon
authors.initials: K
authors.lastname: Kwon
authors.forename: Taeyun
authors.initials: T
authors.lastname: Kwon
authors.forename: Jongbum
authors.initials: J
authors.lastname: Seo
authors.forename: Woo-Jin
authors.initials: WJ
authors.lastname: Chang
authors.forename: Hakhyun
authors.initials: H
authors.lastname: Nam
authors.forename: Geun Sig
authors.initials: GS
authors.lastname: Cha
authors.forename: Moon Hee
authors.initials: MH
authors.lastname: Choi
authors.forename: Dae Sung
authors.initials: DS
authors.lastname: Yoon
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000627:Aminophenols / Q000378:metabolism; D000814:Aniline Compounds / Q000378:metabolism; D002097:C-Reactive Protein / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D004867:Equipment Design; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D008962:Models, Theoretical; D009943:Organophosphorus Compounds / Q000378:metabolism
chemical_list: D000627:Aminophenols; D000814:Aniline Compounds; D009943:Organophosphorus Compounds; C068798:4-aminophenylphosphate; D002097:C-Reactive Protein; D000469:Alkaline Phosphatase