title: Sensitivity enhancement of pH indicator and its application in the evaluation of fish freshness.
abstract: The sensitivity of pH indicators is always confined in acidic solvents used during the immobilization because of the large deviation from their color transition points. By regulating the pH of indicators using organic acid or base, the color transition points of indicators could be readily achieved and the sensitivity could be greatly enhanced. In this study, bromophenol blue was selected as an example to interpret this improvement. And Hue, Saturation and Value (HSV) color model was applied to obtain digital color information of pH indicators. In addition, other two kinds of pH indicators were chosen and regulated to their color transition points as well. The resultant indicators together with the original ones were composed to a colorimetric sensor array and utilized to determine fish freshness. Compared with the original indicators, much higher sensitivity in the detection of fish freshness was obtained by the pH regulated indicators.
authors.affiliation: School of Food Science & Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, PR China; Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China.
authors.forename: Wen
authors.initials: W
authors.lastname: Sun
authors.affiliation: Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Food Science & Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.affiliation: School of Food Science & Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, PR China.
authors.forename: Shan
authors.initials: S
authors.lastname: Xiao
authors.affiliation: School of Food Science & Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, PR China. Electronic address: wangjh@dlpu.edu.cn.
authors.forename: Jihui
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China; Key Lab of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China. Electronic address: fengl@dicp.ac.cn.
authors.forename: Liang
authors.initials: L
authors.lastname: Feng
mesh_terms: D000818:Animals; D003124:Colorimetry / Q000295:instrumentation*; D005029:Ethylenediamines / Q000032:analysis; D063427:Food Quality; D006851:Hydrochloric Acid / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D010473:Perciformes; D012997:Solvents / Q000737:chemistry
chemical_list: D005029:Ethylenediamines; D012997:Solvents; C031234:ethylenediamine; D006851:Hydrochloric Acid
keywords: Color transition point; Fish freshness; Sensitivity; pH indicator