Dual Enhancement with a Nanoparticle-Based Lateral Flow Biosensor for the Determination of DNA

ABSTRACTAn attractive methodology for the one-step signal amplification in a gold nanoparticle-based lateral flow biosensor was successfully applied for nucleic acid determination. This relatively new methodology, namely the “dual gold signal enhancement method” utilizes two gold nanoparticle-antibody conjugates, responsible for both the oligonucleotide detection, as well as a significant increase on the signal intensity of the biosensors’ test zone. Herein, the first conjugate consisted of anti-biotin antibody on gold nanoparticles, blocked with bovine serum albumin and the second conjugate contained anti-bovine serum albumin antibody on gold nanoparticles of different sizes, compared to the first conjugate. Any biotinylated oligonucleotide (polymerase chain reaction or oligonucleotide ligation reaction products) may be efficiently detected. The gold nanoparticle size was found to be the critical factor for the signal formation for the biosensor test and control zones. Gold nanoparticles with relative si...