Quantum dot nanocrystals having guanosine imprinted nanoshell for DNA recognition

Area of Science:

• Nanotechnology
• Biotechnology
• Materials Science

Background:

• Molecular imprinted polymers (MIPs) are gaining traction as recognition elements in sensor technology.
• MIP nanoparticles offer unique advantages for sensing applications.
• Developing selective and sensitive DNA recognition systems is crucial for diagnostics.

Purpose of the Study:

• To develop a novel nanosensor for selective DNA recognition using molecular imprinting.
• To functionalize cadmium sulfide (CdS) quantum dots (QDs) with a thiol ligand-capping method.
• To create a shape-selective cavity for guanosine recognition via metal coordination-chelation.

Main Methods:

• A novel thiol ligand-capping method using polymerizable methacryloylamido-cysteine (MAC) attached to CdS QDs.
• Reconstruction of surface shells using synthetic host polymers via molecular imprinting.
• Utilizing methacryloylamidohistidine-platinium (MAH-Pt(II)) as a metal-chelating monomer for guanosine templating.
• Analysis of binding affinity using Langmuir and Scatchard methods.

Main Results:

• Successful formation of a shape-selective cavity for guanosine and its analogues.
• Demonstrated selective binding to guanosine nucleotide (K(a) = 4.841x10^6 mol L^-1) and guanine base (K(a) = 0.894x10^6 mol L^-1).
• The guanosine-imprinted nanocrystals showed higher affinity for single-stranded DNA (ssDNA) than double-stranded DNA (dsDNA).

Conclusions:

• The developed CdS QD nanosensor with MIPs exhibits high selectivity and affinity for guanosine.
• The sensor demonstrates potential for distinguishing between single-stranded and double-stranded DNA.
• This approach offers a promising platform for developing advanced DNA-based sensors.