Design and Use of a Gold Nanoparticle-Carbon Dot Hybrid for a FLIM-Based IMPLICATION Nano Logic Gate.

ABSTRACT

The interest in nanomaterials resides in the fact that they can be used to create smaller, faster, and more portable systems. Nanotechnology is already transforming health care. Nanoparticles are being used by scientists to target malignancies, improve drug delivery systems, and improve medical imaging. Integration of biomolecular logic gates with nanostructures has opened new paths in illness detection and therapy that need precise control of complicated components. Most studies have used fluorescence intensity techniques to implement the logic function. Its drawbacks, mainly when working with nanoparticles in intracellular media, include fluctuations in excitation power, fluorophore concentration dependence, and interference from cell autofluorescence. We suggest using fluorescence lifetime imaging microscopy (FLIM) in order to circumvent these constraints. Designing a nanohybrid composed of gold nanoparticles (AuNPs) and red-emitting carbon dots (CDs) can be used to develop a FLIM-based logic gate that can respond to multiple input parameters. Our findings indicate a nanohybrid that can serve as a nano-computer to receive and integrate chemical and biochemical stimuli and produce a definitive output measured by FLIM. This can open a new research avenue for enhanced diagnostics and therapy that require complicated factor handling and precise control. The AuNPs are conjugated to CDs' surfaces through a strong covalent linkage. The AuNP-CD nanohybrid shows fluorescence lifetime (FLT) quenching of pristine CDs after conjugation to AuNPs. The FLT was reduced from 3.61 ± 0.037 to 2.48 ± 0.040 ns. This quenched FLT can be recovered back by using trypsin as a recovering agent, giving us a reversible logic output. The FLT was recovered to 3.01 ± 0.01 ns after trypsin addition. This "on-off-on" response can be used to construct the IMPLICATION logic gate.