Highly Efficient On-Chip Photothermal Cell Lysis for Nucleic Acid Extraction Using Localized Plasmonic Heating of Strongly Absorbing Au Nanoislands

Abstract

Cell lysis servesas an essential role in the sample preparationfor intracellular material extraction in lab-on-a-chip applications.However, recent microfluidic-based cell lysis chips still face severaltechnical challenges such as reagent removal, complex design, andhigh fabrication cost. Here, we report highly efficient on-chip photothermalcell lysis for nucleic acid extraction using strongly absorbed plasmonicAu nanoislands (SAP-AuNIs). The highly efficient photothermal celllysis chip (HEPCL chip) consists of a PDMS microfluidic chamber anddensely distributed SAP-AuNIs with large diameters and small nanogaps,allowing for broad-spectrum light absorption. The SAP-AuNIs inducephotothermal heat, resulting in a uniform temperature distributionwithin the chamber and rapidly reaching the target temperature forcell lysis within 30 s. Furthermore, the localized plasmonic heatingof SAP-AuNIs expeditiously triggers phase transition and photoporationin the directly contacted lipid bilayer of the cell membrane, resultingin rapid and highly efficient cell lysis. The HEPCL chip successfullylysed 93% of PC9 cells at 90 & DEG;C for 90 s without nucleic aciddegradation. This on-chip cell lysis offers a new sample preparationplatform for integrated point-of-care molecular diagnostics.