An extracellular vesicle characterization and analysis device in terms of their size, phenotype, and cargo content is provided. A method performed with the device to quantify the heterogeneity of extracellular vesicle samples both in terms of size and cargo content and further quantify the purity of extracellular vesicles based on their phenotype and cargo content is further provided. The extracellular vesicle characterization and analysis device includes an atomic force microscope and confocal Raman spectrometer subsystems that will present the phenotypic characterization and cargo analysis of extracellular vesicles, respectively. By processing the topographic images obtained by atomic force microscopy with image processing methods and analyzing them, the dimensional heterogeneity of the extracellular vesicle samples can be quantified and information about their purity can be presented. The confocal Raman spectrometer applies the tip-enhanced Raman spectrum method, performs a heterogeneity quantification and provides data on the purity of the sample.

A detection substrate of surface-enhanced Raman scattering including a substrate, pillar structures, and target-analyte linking substances are provided. The pillar structures are disposed on the substrate. The pillar structure has a Raman active surface. The ratio of a maximum length of the top-view pattern of the pillar structures to a gap between the adjacent pillar structures ranges from 0.2 to 0.4. The target-analyte linking substances are disposed on the pillar structures.

The present disclosure provides a sensor substrate capable of detecting a trace amount of an analyte. This sensor substrate according to the present disclosure is a sensor substrate comprising a metal microstructure that generates surface plasmon when irradiated with excitation light. The metal microstructure is composed of a plurality of protrusions disposed in a planar shape. The plurality of the protrusions are disposed in such a manner that imaginary lines V each passing through a center between adjacent protrusions draw a honeycomb shape in a plan view. Each of the plurality of the protrusions has a substantially hexagonal shape in the plan view. A depth in a thickness direction of the sensor substrate of a gap present between the adjacent protrusions is larger than a radius of an imaginary circle inscribed in a hexagon forming the honeycomb shape.

A detection device for virus detection is provided, which includes: a carrier including a recess; and a metal layer disposed in the recess and having a contact angle ranging from 0 degrees to 10 degrees, wherein a plurality of cavities are formed on a first surface of the metal layer opposite to a second surface of the metal layer facing the carrier, the plurality of cavities are arranged in an array, and a plurality of first protrusions are formed on the first surface of the metal layer and near to the plurality of cavities. In addition, a detection system for virus detection comprising the aforesaid detection device, a method for detecting viruses using the aforesaid detection device, and a method for preparing the detection device are also provided.

A thin aluminum film substrate and microarrays thereof including a substrate and a thin film of aluminum deposited on the substrate for surface plasmon resonance analysis. Methods of forming the thin aluminum film substrate and microarrays including providing a substrate, using electron-beam physical vapor deposition (EBPVD) to deposit a thin film of Al on a surface of the substrate. Also disclosed are methods of detecting an analyte, wherein a functionalized surface of the thin aluminum film includes a biomolecule and the methods include applying a sample including the analyte to the thin aluminum film substrate, and using surface plasmon resonance (SPR) spectroscopy to detect molecular interactions between the biomolecule and the analyte at a surface of the thin aluminum film substrate. In some examples, an unmodified Al film with an Al.sub.2O.sub.3 layer is effective in enriching phosphorylated peptides. In some examples, a coating of an ionic polymer is used to analyze charged-based interactions of biomolecules.

Methods to detect contaminants in a solution and applications thereof are described. Generally, solutions are printed onto a substrate and then imaged via Raman spectroscopy, which can be utilized to detect signals derived from contaminants.

Embodiments relate to a bioagent capture and identification system including a microfluidic platform for label-free, size-based capture, enrichment, and optical profiling of bioagents using vertically aligned carbon nanotubes coated in gold nanoparticles. Bioagent identification can be automated using machine learning. Captured bioagents remain viable after capture and analysis. In the nanotube fabrication process, catalyst precursor layers are fabricated using patterned stamps. In addition, nanotube diameter and density are increased by increasing the concentration of metal content in the catalyst precursor layer.

The present disclosure provides a technique for quantitatively detecting alkaline phosphatase (ALP) activities in seawater and other aquatic environments, based on surface-enhanced Raman spectroscopy by taking 5-bromo-4-chloro-3-indolyl phosphate (BCIP) as a substrate and dimethyl sulfoxide (DMSO) as an internal standard. Results show that ALP activity has a good linear correlation with the intensity ratio of a characteristic Raman peak to that of the internal standard peak (600 cm.sup.−1/677 cm.sup.−1) (R.sup.2=0.977). The technique was successfully applied to detect ALP activity of a seawater sample. By extension this technique can also be used in detecting the activity of other microbial extracellular enzymes (e.g., aminopeptidase) in seawater and thus, lays a solid scientific foundation for in-situ detection of the activities of other extracellular enzymes in seawater and other aquatic environments.

A Raman multi-gas detection system including an enhancement unit coupled between a light source and a detector. The enhancement unit includes a nanongrid having a plurality of nanogaps. A gas is coupled to the enhancement unit and is configured to flow through the plurality of nanogaps of the nanogrid. The nanogrid comprises one or more plasmon-active materials. The light source is configured to generate plasmon-enhanced electric fields in the plurality of nanogaps of the nanogrid to induce enhanced Raman scattering of the constituent molecules in the gas within the plurality of nanogaps such that a plurality of different constituent molecules in the gas can be detected. In one embodiment, a molecule in the gas is configured to scatter the light from the light source at a rate more than 1000 times greater than in the free space in the enhancement unit.

A fabrication method of a SERS substrate includes (a) preparing a hydrophilic membrane; (b) dipping the hydrophilic membrane in an alcohol; (c) immersing the hydrophilic membrane in a chloride ion aqueous solution; and (d) depositing Ag or Au nanoparticles on the hydrophilic membrane by suction filtration to form the SERS substrate. The hydrophilic membrane includes 10˜20 wt % PVDF, PTFE, PC, PES, nylon, or mixtures thereof, 10˜20 wt % PVP, and 0.2˜1.6 wt % PMMA, PHEMA, or mixtures thereof.