Thermally stable and uniform DNA amplification with picosecond laser ablated graphene rapid thermal cycling device

Abstract

Rapid thermal cycling (RTC) in an on-chip device can perform DNA amplification in vitro through precise thermal control at each step of the polymerase chain reaction (PCR). This study reports a straightforward fabrication technique for patterning an on-chip graphene-based device with hole arrays, in which the mechanism of surface structures can achieve stable and uniform thermal control for the amplification of DNA fragments. A thin-film based PCR device was fabricated using picosecond laser (PS-laser) ablation of the multilayer graphene (MLG). Under the optimal fluence of 4.72 J/cm 2 with a pulse overlap of 66%, the MLG can be patterned with arrays of 250 μm 2 hole surface structures. A 354-bp DNA fragment of VP1, an effective marker for diagnosing the BK virus, was amplified on an on-chip device in less than 60 min. A thin-film electrode with the aforementioned MLG as the heater was demonstrated to significantly enhance temperature stability for each stage of the thermal cycle. The temperature control of the heater was performed by means of a developed programmable PCR apparatus. Our results demonstrated that the proposed integration of a graphene-based device and a laser-pulse ablation process to form a thin-film PCR device has cost benefits in a small-volume reagent and holds great promise for practical medical use of DNA amplification.

Artefact Profiling: Panomics Approaches for Understanding the Materiality of Written Artefacts

“…In the past, both methods could be applied to detect both small polar molecules and larger peptides, as well as proteins in biological materials [ 94 , 95 , 96 ]. Intact DNA molecules could also be removed from organic materials using an IR laser [ 97 ]. At the present time, it is difficult to estimate whether a transfer of such a technical strategy to old materials is possible and how high the information content is in comparison to the other methods presented since there is currently no experience in this regard.…”