Competitive amperometric immunosensor based on covalent linking of a protein conjugate to dendrimer-functionalised nanogold substrate for the determination of 2,4,6-trinitrotoluene.
A new amperometric immunosensor for 2,4,6-trinitrotoluene based on the working principle of competitive enzyme-linked immunosorbent assay was developed and characterised. An electrodeposited nanogold substrate was functionalised by deposition of self-assembled monolayers of 2-aminoethanethiol as linkers for the subsequent immobilisation of polyamidoaminic dendrimers. Our approach makes use of those dendrimers to anchor a trinitrobenzene-ovalbumin conjugate on the electrode surface. The immunosensor was tested and validated for the determination of 2,4,6-trinitrotoluene showing high selectivity with respect to other nitroaromatic compounds, a limit of detection of 4.8 ng/mL and a limit of quantitation of 6 ng/mL. The immunosensor was tested for the quantification of the analyte in spiked soils and in a real sample of post-blast soil, evidencing a good recovery rate (113 %).
Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Università di Parma, Parma, Italy. marco.giannetto@unipr.it
Marco
M
Giannetto
Elisabetta
E
Maiolini
Elida Nora
EN
Ferri
Stefano
S
Girotti
Giovanni
G
Mori
Maria
M
Careri
D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D050091:Dendrimers / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D010047:Ovalbumin / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D014303:Trinitrotoluene / Q000032:analysis*
D050091:Dendrimers; D012989:Soil Pollutants; D014303:Trinitrotoluene; D006046:Gold; D010047:Ovalbumin