title: rhEPO/EPO discrimination with ultrasensitive electrochemical biosensor based on sandwich-type nano-Au/ZnO sol-gel/nano-Au signal amplification.
abstract: This research established a non-labeled electrochemical biosensor for discrimination of recombinant human erythropoietin (rhEPO) and endogenous erythropoietin (EPO). We prepared a glassy carbon electrode (GCE) modified by a unique sandwich-like nano-Au/ZnO sol-gel/nano-Au compound membrane for signal amplification. The porous sol-gel structure facilitates protein activity maintenance and thermostability. Nano-Au is characterized by a large specific surface area, high surface activity, high absorbability, and good electro-conductivity and biocompatibility. By combining the advantages of both ZnO sol-gel and nano-Au, the amount of erythropoietin receptor (EPOR) increased substantially, and electron transfer of EPOR protein and electrode surface increased accordingly. In the present study, the effects of experimental conditions such as nano-Au electrodeposition time and nano-Au concentration were investigated by cyclic voltammetry, and the process of GCE modification was characterized electrochemically. We successfully developed a new method for electrochemical detection of trace rhEPO/EPO. More importantly, the response current change (ΔI) of the nano-Au/ZnO sol-gel/nano-Au modified GCE increases 3-fold when compared with that of the unmodified electrode and the sensor detection sensitivity increases significantly. In conclusion, this electrochemical biosensor is simple to prepare and allows fast, accurate, and specific detection of trace rhEPO in clinical monitoring and stimulant discrimination.
authors.affiliation: Department of Laboratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing 400038, PR China. Electronic address: zlqtmmu@gmail.com.
authors.forename: Liqun
authors.initials: L
authors.lastname: Zhang
authors.forename: Yunxia
authors.initials: Y
authors.lastname: Wang
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Shi
authors.forename: Kun
authors.initials: K
authors.lastname: Deng
authors.forename: Weiling
authors.initials: W
authors.lastname: Fu
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D004921:Erythropoietin / Q000032:analysis / Q000097:blood*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry; D044367:Phase Transition; D011994:Recombinant Proteins / Q000032:analysis / Q000097:blood; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D011994:Recombinant Proteins; D004921:Erythropoietin; D006046:Gold; D015034:Zinc Oxide
keywords: Electrochemical; Erythropoietin (EPO); Nano-Au; Sensor; Signal amplification