title: Colorimetric sensor array with unmodified noble metal nanoparticles for naked-eye detection of proteins and bacteria.
abstract: Herein we report a novel strategy for the detection and identification of proteins using unmodified noble metal nanoparticles. Five gold nanoparticles (AuNPs) and two silver nanoparticles (AgNPs) with different sizes were utilized as sensing elements to create a colorimetric sensor array. In the presence of proteins, the UV-vis absorbance of the noble metal nanoparticles changed due to the interactions between the protein and nanoparticles, producing distinct absorbance response patterns which can be visually detected by the naked eye. The color pattern of the array is a unique "fingerprints" for each protein sample, which can be differentiated by linear discriminant analysis (LDA). Ten different proteins at concentrations of 0.5, 5 and 50 μM have be successfully discriminated. Moreover, the array was also able to discriminate different bacteria at a concentration of 0.05 OD in 200 μL, as well as cancer cells at the level of 5000 cells in 200 μL. This work demonstrates that an unmodified noble metal nanoparticle-based protein detection array has potential for applications in medical diagnostics.
authors.affiliation: School of Life Science and Technology, Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University, 710049, Xi'an, P. R. China. yayanwu@mail.xjtu.edu.cn.
authors.forename: Dongyang
authors.initials: D
authors.lastname: Li
authors.affiliation: School of Life Science and Technology, Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University, 710049, Xi'an, P. R. China. yayanwu@mail.xjtu.edu.cn.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Dong
authors.affiliation: School of Life Science and Technology, Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University, 710049, Xi'an, P. R. China. yayanwu@mail.xjtu.edu.cn.
authors.forename: Bingyu
authors.initials: B
authors.lastname: Li
authors.affiliation: School of Life Science and Technology, Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University, 710049, Xi'an, P. R. China. yayanwu@mail.xjtu.edu.cn.
authors.forename: Yayan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: School of Life Science and Technology, Key Laboratory of Biomedical Information Engineering of Ministry of Education, Xi'an Jiaotong University, 710049, Xi'an, P. R. China. yayanwu@mail.xjtu.edu.cn.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Beijing Key Laboratory for Microanalytical Methods and Instrumentation, Tsinghua University, 100084, Beijing, P. R. China. sczhang@mail.tsinghua.edu.cn.
authors.forename: Sichun
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001419:Bacteria / Q000302:isolation & purification*; D001424:Bacterial Infections / Q000175:diagnosis / Q000382:microbiology; D015374:Biosensing Techniques / Q000295:instrumentation; D045744:Cell Line, Tumor; D003124:Colorimetry / Q000295:instrumentation*; D016002:Discriminant Analysis; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000032:analysis*; D012834:Silver / Q000737:chemistry*
chemical_list: D011506:Proteins; D012834:Silver; D006046:Gold