Abstract: Provided are biosensors, systems and related methods of using the biosensors and systems. The biosensor comprises a field-effect transistor (FET) having a crumpled geometry to effectively increase the detection sensitivity of a target molecule in an ionic solution. A FET having a crumpled semiconductor material channel can form a ?-? interaction with single stranded DNA (ssDNA) for amplification detection applications. Increasing amount of ssDNA in an amplification reaction solution is incorporated into an amplified double stranded DNA, with increasing amplification, resulting in a lower amount of ssDNA primers. The FET is contacted with the amplified solution to electrically detect an amount of ssDNA primer in the amplified solution, thereby detecting amplification based on a decreased amount of ssDNA bound to the FET. Also provided are biosensors that can detect biomolecules more generally, such as protein, polypeptides, polynucleotides, or small molecules.

Abstract: A continuous flow reactor for nanoparticle synthesis comprises a modular system including a plurality of interconnected tubular components for fluid flow therethrough including a first tubular inlet and a second tubular inlet connected to a three-way junction comprising a tubular mixer. A continuous flow method for nanoparticle synthesis comprises flowing a growth solution and a reaction-initiating solution into a mixing portion of a flow reactor to form a mixed solution; flowing the mixed solution through a holding portion of the flow reactor for a predetermined residence time to form a reacted solution comprising nanoparticles; and continuously removing the reacted solution from the flow reactor so as to achieve a throughput of nanoparticles of at least about 0.5 mg/min.

Abstract: A continuous flow reactor for nanoparticle synthesis comprises a modular system including a plurality of interconnected tubular components for fluid flow therethrough including a first tubular inlet and a second tubular inlet connected to a three-way junction comprising a tubular mixer. A continuous flow method for nanoparticle synthesis comprises flowing a growth solution and a reaction-initiating solution into a mixing portion of a flow reactor to form a mixed solution; flowing the mixed solution through a holding portion of the flow reactor for a predetermined residence time to form a reacted solution comprising nanoparticles; and continuously removing the reacted solution from the flow reactor so as to achieve a throughput of nanoparticles of at least about 0.5 mg/min.

Abstract: Surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid (4-MBA) self-assembled monolayers (SAMs) on gold substrates is presented for SAMs onto which gold nanoparticles of various shapes have been electrostatically immobilized. SERS spectra of 4-MBA SAMs are enhanced in the presence of immobilized gold nanocrystals by a factor of 107-109 relative to 4-MBA in solution. Large enhancement factors are a likely result of plasmon coupling between the nanoparticles (localized surface plasmon) and the smooth gold substrate (surface plasmon polariton), creating large localized electromagnetic fields at their interface, where 4-MBA molecules reside in this sandwich architecture. Moreover, enhancement factors depend on nanoparticle shape, and vary by a factor of 102.

Abstract: In one aspect, the invention relates to methods for enhancing a Raman signal comprising the steps of providing a sample comprising a metal surface, an analyte adhered to the surface, and a metallic nanoparticle coupled to the surface, wherein the nanoparticle has a plasmon resonance band; exposing the sample to incident energy of an excitation wavelength; and detecting the Raman signal of the analyte. In a further aspect, the invention relates to a compositiion comprising a metal surface, a functionalized self-assembled monolayer adhered to the surface, wherin the self-assembled monolayer comprises an analyte, and a cetyltrimethylammonium halide-capped metallic nanoparticle coupled to the surface. In a further aspect, the invention relates to a cetyltrimethylammonium bromide-capped gold nanoparticle and a method for preparing same. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Abstract: Surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid (4-MBA) self-assembled monolayers (SAMs) on gold substrates is presented for SAMs onto which gold nanoparticles of various shapes have been electrostatically immobilized. SERS spectra of 4-MBA SAMs are enhanced in the presence of immobilized gold nanocrystals by a factor of 107-109 relative to 4-MBA in solution. Large enhancement factors are a likely result of plasmon coupling between the nanoparticles (localized surface plasmon) and the smooth gold substrate (surface plasmon polariton), creating large localized electromagnetic fields at their interface, where 4-MBA molecules reside in this sandwich architecture. Moreover, enhancement factors depend on nanoparticle shape, and vary by a factor of 102.

Abstract: Surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid (4-MBA) self-assembled monolayers (SAMs) on gold substrates is presented for SAMs onto which gold nanoparticles of various shapes have been electrostatically immobilized. SERS spectra of 4-MBA SAMs are enhanced in the presence of immobilized gold nanocrystals by a factor of 107-109 relative to 4-MBA in solution. Large enhancement factors are a likely result of plasmon coupling between the nanoparticles (localized surface plasmon) and the smooth gold substrate (surface plasmon polariton), creating large localized electromagnetic fields at their interface, where 4-MBA molecules reside in this sandwich architecture. Moreover, enhancement factors depend on nanoparticle shape, and vary by a factor of 102.

Abstract: Surface enhanced Raman scattering (SERS) spectra of 4-mercaptobenzoic acid (4-MBA) self-assembled monolayers (SAMs) on gold substrates is presented for SAMs onto which gold nanoparticles of various shapes have been electrostatically immobilized. SERS spectra of 4-MBA SAMs are enhanced in the presence of immobilized gold nanocrystals by a factor of 107-109 relative to 4-MBA in solution. Large enhancement factors are a likely result of plasmon coupling between the nanoparticles (localized surface plasmon) and the smooth gold substrate (surface plasmon polariton), creating large localized electromagnetic fields at their interface, where 4-MBA molecules reside in this sandwich architecture. Moreover, enhancement factors depend on nanoparticle shape, and vary by a factor of 102.