so id 008 008
Accepted 1 November 2014
Available online 8 November 2014 al i histamine molecules will compete to bind with the antibodies. The captured HRP could then catalyze and commercial enzyme immunoassays (EIAs) [15,16]. However, for enzyme based electrochemical biosensors, as there are many kinds of amines exist in the biological samples, these biosensors ion of insulating the electrode to r the immobilizawere cov oxylic gro trations of sample histamine were mixed with HRP labeled histamine (histamine-HRP), they will compete to bind with the antibodies on the electrode surface. The captured HRP on the electrode surface will catalyze the polymerization of 3,30-dimethoxybenzidine (DB) in the presence of H2O2, leading to the formation of an insulating polymer film, poly(3,30-dimethoxybenzidine) (PDB) onto the electrode surface [22,23]. Thus, the redox current of the electrode in Fe(CN)63/4 solution was decreased, and the ⇑ Corresponding authors at: Department of Dermatology, XiangYa Hospital,
Central South University, Changsha 410008, China. Tel./fax: +86 731 84328478.
E-mail addresses: firstname.lastname@example.org (M. Yang), email@example.com (X. Chen).
Journal of Electroanalytical Chemistry 736 (2015) 88–92
Contents lists availab
Journal of Electroan l sedrogenase) [8–10], immunosensors [11,12], high-performance liquid chromatography (HPLC) , liquid chromatography , the graphene. To carry out the competitive immunoassay, histamine was first labeled with enzyme HRP. When different concen-allergy research for the study of allergic responses and a variety of pathological conditions [5–7].
Different techniques have been reported for the detection of histamine, such as enzyme based electrochemical biosensor utilizing various enzymes (e.g. histamine oxidase and histamine dehyhorseradish peroxidase (HRP) initiated deposit film . Graphene was utilized to modify increase the conductivity of the electrode and fo tion of antibodies. Anti-histamine antibodies immobilized onto graphene based on the carbhttp://dx.doi.org/10.1016/j.jelechem.2014.11.002 1572-6657/ 2014 Elsevier B.V. All rights reserved.alently ups onHistamine is a low molecular weight organic compound and an important biological marker in body fluid [1,2]. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in different tissues [3,4]. It is acted as a chemical mediator in inflammation, gastric acid secretion and neural modulation. So the sensitive and selective detection of histamine is of great importance in clinical diagnosis and
EIAs, its sensitivity sometimes is not high enough for the detection of ultralow levels of histamine in the samples. On the contrary, compared to these techniques, electrochemical immunosensors has the advantages of high sensitivity, simple instrumentation, low cost and fast response [17–20].
In this work, we developed a competitive electrochemical immunosensor for the sensitive detection of histamine based onKeywords:
Graphene 1. Introductionthe polymerization of 3,30-dimethoxybenzidine (DB) in the presence of H2O2 to produce the deposition of an insulating polymer film, poly(3,30-dimethoxybenzidine) (PDB) onto electrode surface. The deposited insulating PDB film resulted in the decrease of the electrochemical current of the electrode in Fe(CN)63/4 solution, and the current change is proportional to the concentration of histamine detected. The proposed immunosensor displays wide linear range towards histamine detection (1 pg/mL–1 ng/mL) with a detection limit of 0.5 pg/mL. The immunosensor was applied to the detection of histamine in serum samples with satisfactory results. 2014 Elsevier B.V. All rights reserved. have the disadvantages of poor selectivity. The HPLC and liquid chromatography methods require complicated instruments. ForReceived 28 July 2014
Received in revised form 30 October 2014 electrode and horseradish peroxidase (HRP) initiated deposition of insulating film was developed. After the immobilization of anti-histamine antibodies onto graphene surface, free histamine and HRP taggedShort Communication
Competitive electrochemical immunosen of histamine based on horseradish perox of insulating film
Minghui Yang a,b,⇑, Jianglin Zhang a, Xiang Chen a,⇑ aDepartment of Dermatology, XiangYa Hospital, Central South University, Changsha 410 bCollege of Chemistry and Chemical Engineering, Central South University, Changsha 41 a r t i c l e i n f o
Article history: a b s t r a c t
Competitive electrochemic journal homepage: www.er for the detection ase initiated deposition , China 3, China mmunosensor for the detection of histamine based on graphene modified le at ScienceDirect alytical Chemistry vier .com/locate / je lechem the increase the sensitivity of the immunosensor. The graphene modified electrode was first characterized in Fe(CN)63/4 solution by cyclic voltammatry (CV). As shown in Fig. 1, compared to the bare electrode (curve a), the redox current of the graphene modified electrode was increased (curve b), indicating the modification of the electrode with graphene increased the conductivity of the electrode.
After the immobilization of anti-histamine antibodies onto graphene surface, the mixture containing different concentrations of free histamine and a specific concentration of histamine-HRP conjugate was applied onto the electrode surface. Free histamine and histamine-HRP conjugate will then compete to bind with the immobilized antibodies. As HRP could catalyze DB into insulate
PDB to be deposited onto electrode surface, the redox current of the electrode will then be decreased. With the increasing of free histamine concentration, the histamine-HRP conjugate that captured onto the electrode will be decreased. Through such method, an ‘‘off–on’’ type electrochemical immunosensor was proposed for nalytical Chemistry 736 (2015) 88–92 89change of the redox current was proportional to the concentration of histamine detected. 2. Experimental 2.1. Reagents and apparatus