title: Molecularly Imprinted Polymer-Based Plasmonic Immunosandwich Assay for Fast and Ultrasensitive Determination of Trace Glycoproteins in Complex Samples.
abstract: Glycoproteins play significant roles in many biological processes. Assays of glycoproteins have significant biological importance and clinical values, for which immunoassay has been the workhorse tool. However, immunoassay suffers from some disadvantages, such as poor availability of high-specificity antibodies and limited stability of biological reagents. Herein, we present an antibody-free and enzyme-free approach, called molecularly imprinted polymer (MIP)-based plasmonic immunosandwich assay (PISA), for fast and ultrasensitive detection of trace glycoproteins in complex samples. A gold-based boronate affinity MIP array was used to specifically extract the target glycoprotein from complex samples. After washing away unwanted species, the captured glycoprotein was labeled with boronate affinity silver-based Raman nanotags. Thus, sandwich-like complexes were formed on the array. Upon being shined with a laser beam, the gold-based array generated a surface plasmon wave, which significantly enhanced the surface-enhanced Raman scattering (SERS) signal of the silver-based Raman nanotags. The MIP ensured the specificity of the assay, while the plasmonic detection provided ultrahigh sensitivity. Erythropoietin (EPO), a glycoprotein hormone that controls erythropoiesis or red blood cell production, was employed as a test glycoprotein in this study. Specific detection of EPO in solution down to 2.9 × 10-14M was achieved. Using a novel strategy to accommodate the method of standard addition to a logarithmic dose-response relationship, EPO in human urine was quantitatively determined by this approach. The analysis time required only 30 min in total. This approach holds promising application prospects in many areas, such as biochemical research, clinical diagnosis, and antidoping analysis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Tu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Pir
authors.initials: P
authors.lastname: Muhammad
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Shuangshou
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Danyang
authors.initials: D
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University , 163 Xianlin Avenue, Nanjing 210023, China.
authors.forename: Zhen
authors.identifier: 0000-0002-8440-2554
authors.initials: Z
authors.lastname: Liu
mesh_terms: D004921:Erythropoietin / Q000032:analysis / Q000652:urine*; D006023:Glycoproteins / Q000032:analysis / Q000652:urine; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D054802:Molecular Imprinting / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: C554270:EPO protein, human; D006023:Glycoproteins; D011108:Polymers; D004921:Erythropoietin; D012834:Silver; D006046:Gold