title: Selective nonenzymatic bilirubin detection in blood samples using a Nafion/Mn-Cu sensor.
abstract: The specific detection of biological organics without the use of an enzyme is challenging, and it is crucial for analytical and clinical chemistry. We report specific nonenzymatic bilirubin detection through the catalytic oxidation of bilirubin molecule on the Nafion/Mn-Cu surface. The catalytic ability, true surface area, morphology, crystallinity, composition, and oxidation state of the sensor surface were assessed using voltammetry, coulometry, XPS, XRD, Brunauer-Emmett-Teller (BET), SEM, EDXS, and TOF-SIMS experiments. The results showed that the surface was composed of microporous Mn-Cu bimetallic crystal in flake shape with a large BET surface area (3.635 m(2)g(-1)), where the surface area and crystallinity mainly affected the sensor performance. Product analysis of the catalytic reaction on the sensor probe revealed a specific two-electron oxidation of dipyrromethane moiety to dipyrromethene in the bilirubin molecule. Experimental variables affecting the analysis of bilirubin were optimized in terms of probe composition, temperature, pH, and potential. At the optimized condition, the dynamic range was between 1.2 μM and 0.42 mM, which yielded the equation of ΔI (μA)=(1.03 ± 0.72)+(457.0 ± 4.03) [C] (mM) with 0.999 of correlation coefficient, and the detection limit was 25.0 ± 1.8 nM (n=5, k=3). The stability test, interference effects, and analysis of real clinical samples, human whole blood and certified serum samples were demonstrated to confirm the reliability of the proposed bilirubin sensor.
authors: Department of Chemistry and Institute of BioPhysio Sensor Technology (IBST), Pusan National University, Busan 609-735, South Korea.
authors: Hui-Bog
authors: HB
authors: Noh
authors: Busan Center, Korea Basic Science Institute (KBSI), Busan 609-735, South Korea.
authors: Mi-Sook
authors: MS
authors: Won
authors: Department of Chemistry and Institute of BioPhysio Sensor Technology (IBST), Pusan National University, Busan 609-735, South Korea. Electronic address: ybshim@pusan.ac.kr.
authors: Yoon-Bo
authors: YB
authors: Shim
mesh_terms: D001663:Bilirubin / Q000097:blood*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003300:Copper / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D008345:Manganese / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D005465:Fluorocarbon Polymers; C040402:perfluorosulfonic acid; D008345:Manganese; D003300:Copper; D001663:Bilirubin
keywords: Amperometric biosensor; Catalytic reaction mechanism; Nafion/Mn–Cu sensor; Nonenzymatic bilirubin sensor