Functionalized polyacrylonitrile‐nanofiber based immunosensor for Vibrio cholerae detection

Abstract

Polyacrylonitrile nanofibers (PANnf's) were electrospun directly onto an indium tin oxide (ITO)‐coated glass substrate. The PANnf/ITO electrode was partially hydrolyzed with an NaOH aqueous solution at ambient temperature to convert the nitrile groups of the PANnf's into carboxyl groups was confirmed by Fourier transform infrared spectroscopy. Furthermore, 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide–N‐hydroxy succinimide chemistry was used to activate the COOH groups of PANnf's for the covalent co‐immobilization of monoclonal antibodies against Vibrio cholerae and bovine serum albumin for V. cholerae toxin detection. Structural, functional, and electrochemical studies of the PANnf/ITO electrode and BSA/Ab/PANnf/ITO immunoelectrode were performed, and found a uniform distribution of nanofibers with diameter of 325 ± 7.7% nm. The electrochemical response studies showed an improved sensing performance of the immunoelectrode with a detection of 6.25–500 ng/mL, a low limit of detection of 0.22 ng/mL, a sensitivity of 90 nA ng−1 mL cm−2, an association constant of 45.2 ng/mL, and a dissociation constant of 8 ng/mL. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44170.

Electrochemical Affinity Biosensors Based on Selected Nanostructures for Food and Environmental Monitoring

“…Label-free and single-immunoreaction biosensors have been reported using electrode substrates nanostructured with PPI-AuNP nanocomposite [ 81 ], PANnf’s [ 82 ], ZnO NPs [ 83 ], CNTs [ 84 ] and CNFs [ 85 ] for Vibrio cholerae [ 82 ] and its characteristic toxins [ 81 , 82 , 85 ] or antibodies [ 84 ]. Although all these immunosensors exhibit good analytical characteristics in terms of sensitivity and selectivity, none has been applied to the analysis of real samples.…”

Recent Advances in Electrospun Nanofiber Interfaces for Biosensing Devices

“…The most common methods proposed to generate bioreceptor-NF hybrid assemblies consist in the attachment of the biomolecules onto the fiber surface by physical or chemical sorption, covalent binding, cross-linking or entrapment in a membrane. This approach has been extensively used to immobilize enzymes [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], antibodies [ 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], DNA strands [ 71 , 72 , 73 ] and aptamers [ 74 , 75 ]. Another way to proceed, more specifically developed for enzyme biosensors, consists in entrapping the bioactive molecules inside the NFs by electrospinning a blend of enzymes and polymer [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , ...…”

Bovine Serum Albumin-Dependent Charge-Transfer Kinetics Controls the Electrochemical Immunosensitive Detection: Vibrio cholerae as a Model Bioanalyte

“…For example, culture method can take up to 8 days to get the results while, according to literature [4], cholera kills within 12 to 24 h if not treated. There are many other methods such as enzyme-linked immunosorbent assay [5], polymerase chain reaction (PCR) [6,7], and electrochemical methods [8][9][10][11][12][13][14][15]. Of all the aforementioned techniques, electrochemistry gives excellent promise for fast detection, simplicity, sensitivity, selectivity, and ability to miniaturize the process for the development of hand-held point-of-care diagnostic devices.…”

“…Thus, several researchers have reported several electrode platforms for the immobilization of cholera immunosensors. These electrode platforms include graphene [8], liposomes and poly (3,4ethylenedioxythiophene)-coated carbon nanotubes [9], dendrimers integrated with gold nanoparticles [10], zinc oxide [11], polyacrylonitrile (PAN) nanofibres [12], copper (II) complex with polypyrrole-nitrilotriacetic acid on carbon nanotubes [13], carbon nanofibres (CNF) [14], and onionlike carbon modified with PAN (OLC-PAN) [15]. In electrochemistry, to be redox-active, a material must be able to lose or gain electrons (i.e., conducting), while a redox-inactive (or redox-silent) material is insulating.…”

“…Bovine serum albumin (BSA) is an important protein which is popularly used to block non-specific sites in the immunosensing platforms [9][10][11][12][13][14][15][16][17]. In electrochemical immunosensors, the sensing mechanism is generally dominated by capacitance (i.e., non-Faradaic detection) due to the redox-inactivity of the electrode platform upon which the antibody or antigen is immobilized.…”