title: Universal metal-semiconductor hybrid nanostructured SERS substrate for biosensing.
abstract: We demonstrate here a novel high surface area GaN nanowall network substrate with plasmonic Ag nanodroplets, that can be employed as a highly sensitive, reproducible, and charge independent SERS substrate. The uniformity of the size and distribution of the Ag droplets and the absence of linker ligands result in large near-field intensity, while the GaN nanowall network morphology provides multiple reflections for signal enhancement. FDTD calculations simulate the observed hot-spot distribution and reiterate the higher performance of this hybrid substrate over conventional ones. Our studies on oppositely charged proteins provide a proof of concept for employing this as a versatile charge independent label free SERS substrate for trace biomolecule detection.
authors.affiliation: Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India.
authors.forename: Soumik
authors.initials: S
authors.lastname: Siddhanta
authors.forename: Varun
authors.initials: V
authors.lastname: Thakur
authors.forename: Chandrabhas
authors.initials: C
authors.lastname: Narayana
authors.forename: S M
authors.initials: SM
authors.lastname: Shivaprasad
mesh_terms: D001704:Biopolymers / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation; D012666:Semiconductors; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D001704:Biopolymers; D012834:Silver