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.

Imaging the rotational mobility of carbon dot-gold nanoparticle conjugates using frequency domain wide-field time-resolved fluorescence anisotropy

“…Several mechanisms responsible for the change of fluorescence properties in CDs have already been applied for sensing applications. 63 – 65 The near-field interactions of CDs and the AuNPs can cause the spectral emission of the fluorescence to change wavelengths making CDs-Au constructs suitable FLIM probes (as is evident by the fundamental Strickler-Berg formula, 2 which is discussed in Appendix B in the Supplementary Material ).…”

Carbon dots@noble metal nanoparticle composites: research progress report

“…In the presence of AuNP, the fluorescence of CDs is quenched, while in the presence of microRNA-155, the fluorescence ratio at 489 and 665 nm is enhanced again, which means that this composite system can be used for imaging of microRNA-155 in living cells. 177 In addition, this composite material can be used for the effective diagnosis and treatment of many diseases. For example, a nanohybrid composed of AuNPs conjugated to the surface of CDs through strong covalent bonds was designed.…”

Recent Advances in the Spintronic Application of Carbon-Based Nanomaterials

“…Similar to the implantation of biological logic-gates [ 37 , 38 , 39 ], graphene nanoflakes (GNFs) have recently gained significant interest due to their use in spintronic devices [ 40 , 41 ]. They allow for the induction of magnetism via boundary states, defects, doped magnetic atoms, or strain.…”