Ultrafast Photonic PCR with All‐Solution‐Processed Ti3C2Tx‐Based Perfect Absorbers

Abstract Polymerase chain reaction (PCR) is a critical tool for nucleic acid amplification in molecular diagnosis and genetic analysis. Point‐of‐care (POC) devices are essential for controlling the spread of infectious diseases, but developing cost‐effective chip‐based PCR systems remains a challenge. This study introduces a photonic PCR chip featuring a perfect metamaterial absorber made of Ti 3 C 2 T x MXene, silicon dioxide (SiO 2 ), and gold nanoparticles (GNP) in a metal‐insulator‐metal (MIM) configuration. Fabricated via a solution‐processing approach, the absorber demonstrates 98% light absorption without the need for expensive lithographic methods. Utilizing a 940 nm infrared (IR) LED, the chip achieves efficient photothermal effects with heating rates of ≈8.3 °C s⁻¹ and cooling rates of ≈7.2 °C s⁻¹ during 30 cycles of λ‐DNA and SARS‐CoV‐2 amplification, transitioning from 65 °C to 95 °C. The low cost and high efficiency of the MXene‐based metamaterial absorbers highlight their potential as key components for ultrafast, energy‐efficient molecular diagnostic chips suitable for on‐site applications.