F. Cao, F. Donnarumma, K.K. Murray, Tip-enhanced laser ablation and capture of DNA, Appl. Surf. Sci. 476 (2019) 658–662. doi:10.1016/j.apsusc.2019.01.104.

Abstract: Tip-enhanced laser ablation was used to extract DNA plasmid for polymerase chain reaction (PCR) amplification. A 532 nm nanosecond laser was directed onto a gold coated atomic force microscopy (AFM) tip 10 nm above a sample surface to ablate a 7.1 kbp green fluorescent protein (GFP) plasmid DNA sample on a glass coverslip. The ablated material was captured on a metal ribbon 300 µm above the sample surface. The ablation craters had diameters from 1 to 2 µm and an average volume of 0.14 µm3. PCR and nested PCR were employed for the amplification of the ablated DNA. The quantity of sample from each ablation crater for PCR amplification was 20 ag.

Tip-enhanced laser ablation and capture of DNA
The proposed technology allows topographical imaging with atomic force microscopy (AFM) and extraction of DNA via tip-enhanced laser ablation using the same tip. Plasmid DNA is imaged with a gold coated tip and extracted using a pulsed laser with a sampling size of 1 µm. The captured DNA can be amplified by polymerase chain reaction (PCR) and nested PCR.