A sensitive and innovative detection method for rapid C-reactive proteins analysis based on a micro-fluxgate sensor system

PLOS ONE, Nov 2019

A sensitive and innovative assay system based on a micro-MEMS-fluxgate sensor and immunomagnetic beads-labels was developed for the rapid analysis of C-reactive proteins (CRP). The fluxgate sensor presented in this study was fabricated through standard micro-electro-mechanical system technology. A multi-loop magnetic core made of Fe-based amorphous ribbon was employed as the sensing element, and 3-D solenoid copper coils were used to control the sensing core. Antibody-conjugated immunomagnetic microbeads were strategically utilized as signal tags to label the CRP via the specific conjugation of CRP to polyclonal CRP antibodies. Separate Au film substrates were applied as immunoplatforms to immobilize CRP-beads labels through classical sandwich assays. Detection and quantification of the CRP at different concentrations were implemented by detecting the stray field of CRP labeled magnetic beads using the newly-developed micro-fluxgate sensor. The resulting system exhibited the required sensitivity, stability, reproducibility, and selectivity. A detection limit as low as 0.002 μg/mL CRP with a linearity range from 0.002 μg/mL to 10 μg/mL was achieved, and this suggested that the proposed biosystem possesses high sensitivity. In addition to the extremely low detection limit, the proposed method can be easily manipulated and possesses a quick response time. The response time of our sensor was less than 5 s, and the entire detection period for CRP analysis can be completed in less than 30 min using the current method. Given the detection performance and other advantages such as miniaturization, excellent stability and specificity, the proposed biosensor can be considered as a potential candidate for the rapid analysis of CRP, especially for point-of-care platforms.

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A sensitive and innovative detection method for rapid C-reactive proteins analysis based on a micro-fluxgate sensor system

March A sensitive and innovative detection method for rapid C-reactive proteins analysis based on a micro-fluxgate sensor system Lei Guo 0 1 2 Zhen Yang 0 2 Shaotao Zhi 0 1 2 Zhu Feng 0 1 2 Chong Lei 0 1 2 Yong Zhou 0 1 2 0 Natural Science Foundation of China (No.61273065), National Science and Technology Support Program (2012BAK08B05), Natural Science Foundation of Shanghai (13ZR1420800), Support fund of Shanghai Jiao Tong University (AgriX2015005), Support fund of Joint research center for advanced aerospace technology of 1 Key Laboratory for Thin Film and Microfahrication of Ministry of Education, Research Institute of Micro/Nano Science and Technology, Shanghai JiaoTong University , Shanghai , China , 2 School of Physics and Electronic Engineering, Xinyang Normal University , Xinyang , China 2 Editor: Jonghoon Choi, Chung-Ang University College of Engineering , REPUBLIC OF KOREA A sensitive and innovative assay system based on a micro-MEMS-fluxgate sensor and immunomagnetic beads-labels was developed for the rapid analysis of C-reactive proteins (CRP). The fluxgate sensor presented in this study was fabricated through standard microelectro-mechanical system technology. A multi-loop magnetic core made of Fe-based amorphous ribbon was employed as the sensing element, and 3-D solenoid copper coils were used to control the sensing core. Antibody-conjugated immunomagnetic microbeads were strategically utilized as signal tags to label the CRP via the specific conjugation of CRP to polyclonal CRP antibodies. Separate Au film substrates were applied as immunoplatforms to immobilize CRP-beads labels through classical sandwich assays. Detection and quantification of the CRP at different concentrations were implemented by detecting the stray field of CRP labeled magnetic beads using the newly-developed micro-fluxgate sensor. The resulting system exhibited the required sensitivity, stability, reproducibility, and selectivity. A detection limit as low as 0.002 μg/mL CRP with a linearity range from 0.002 μg/mL to 10 μg/mL was achieved, and this suggested that the proposed biosystem possesses high sensitivity. In addition to the extremely low detection limit, the proposed method can be easily manipulated and possesses a quick response time. The response time of our sensor was less than 5 s, and the entire detection period for CRP analysis can be completed in less than 30 min using the current method. Given the detection performance and other advantages such as miniaturization, excellent stability and specificity, the proposed biosensor can be considered as a potential candidate for the rapid analysis of CRP, especially for point-of-care platforms. - Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Introduction Modern biomedical research requires accurate, sensitive, and rapid protein measurements to facilitate biomarker discovery [ 1 ], detection [2], monitoring of diseases [3], personalized medicine [ 4 ], and new drug development [ 5 ]. An important application involves measuring the levels of proteins in blood serum, which are biomarkers for disease diagnosis. To date, Shanghai Academy of Spaceflight TechnologyShanghai Jiao Tong University (USCAST2015-2), Natural Science Foundation of Henan Province (162300410233), Support fund of aerospace technology (15GFZ-JJ02-05). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. known protein markers exist for every common form of cancer as well as for a range of cardiac diseases [ 6 ]. An ability to assay the aforementioned biomarker-proteins is of profound value in early diagnosis, as well as in the monitoring of responses for therapeutic intervention [ 7 ]. Specifically, C-reactive proteins (CRP) are extremely important acute-phase proteins and are of particular interest because the presence of abnormal concentrations of CRP in blood is directly linked to various diseases [ 8, 9 ]. Recent studies indicated that CRP is directly involved in cardiovascular diseases [ 10, 11 ], and is the most reliable predictor of cerebral congestion [ 10 ] and myocardial infarction [ 11 ]. In fact, elevated CRP levels are a factor in the diagnosis of several fatal diseases, i.e., in the field of clinical application, CRP levels of 0.003±0.11 μg/mL can be used for the monitoring of coronary heart disease after surgery therapy and a CRP range from 0.005±3 μg/mL can be utilized for the diagnosis of potential risks of acute myocardial infarction. Moreover, Yanbaeva et al [ 12 ] indicated that the CRP-levels of 0.2±11.09 μg/mL are useful for the prediction of chronic obstructive pulmonary disease (COPD) risk. Furthermore, Reitz et al [ 13 ] found that a threshold of about 6 μg/mL can be served to assist in the diagnosis of cerebral small-vessel disease. Thus, highsensitivity and wide linearity range of CRP measurement has the potential to (...truncated)


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Lei Guo, Zhen Yang, Shaotao Zhi, Zhu Feng, Chong Lei, Yong Zhou. A sensitive and innovative detection method for rapid C-reactive proteins analysis based on a micro-fluxgate sensor system, PLOS ONE, 2018, Volume 13, Issue 3, DOI: 10.1371/journal.pone.0194631