Palladium@gold bimetallic nanostructures as peroxidase mimic for development of sensitive fluoroimmunoassay.
In this paper, gold nanoparticles coated with palladium dots (Pd@Au) bimetallic nanostructures have been reported to have a peroxidase like activity which is not found in their monometallic counterparts. Based on this finding, we have developed an immunoassay in which antibody-modified Pd@Au nanostructure catalyzes the dimerization of a fluorogenic substrate for peroxidase, 3-(4-dihydroxy phenyl) propionic acid (HPPA), to generate high fluorescence signal. Specific antibodies against bensulfuron-methyl were generated by using a well characterized bensulfuron-protein conjugate as an immunogen, and the assay was performed in a competitive immunoassay format where Pd@Au nanostructure was bound to secondary antibody to show the peroxidase like activity. The developed immunoassay exhibited an excellent sensitivity showing a dynamic response range from 0.001 to 100 ng mL(-1) for herbicide bensulfuron-methyl with a detection limit of 0.01 ng mL(-1) (n=3). The newly synthesized bimetallic nanostructure shows the advantages of low cost, easy synthesis and tunable catalytic activity, making it a promising substitution of enzyme peroxidase in different applications.
Institute of Microbial Technology (CSIR), Chandigarh 160036, India.
Yogesh
Y
Nangia
Bipul
B
Kumar
Jyotsna
J
Kaushal
C Raman
CR
Suri
D015200:Fluoroimmunoassay / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006540:Herbicides / Q000032:analysis* / Q000276:immunology; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010165:Palladium / Q000737:chemistry*; D009195:Peroxidase / Q000737:chemistry; D013453:Sulfonylurea Compounds / Q000032:analysis* / Q000276:immunology
D006540:Herbicides; D013453:Sulfonylurea Compounds; D010165:Palladium; D006046:Gold; C071475:methyl bensulfuron; D009195:Peroxidase