Abstract: A hand-held or portable SPR device focuses light at two or more positions on a noble metal sensor surface, functionalized to enable detection of different SPR curves and their respective minima. The detection is accomplished substantially simultaneously by obtaining SPR signals contemporaneously from the different locations on the sensor surface, on the same sensor. The SPR device may incorporate multiple light sources or a single light source with a beam that is shifted by deflectors in seriatim to focus on different positions on along the functionalized sensor surface. To control wettability of the sensor surface (to augment multiplexing), the sensor surface may include i) the addition of surface assembled monolayers (SAMs) and ii) surface bombardment by gaseous plasmas, most notably O2.

Abstract: Systems and methods for determining the osmolarity of a sample are provided. Aspects of the subject methods include contacting a sensing surface of a surface plasmon resonance based sensor with a sample, and generating one or more data sets at at least two wavelengths over a time interval, wherein the data sets are used to determine the osmolarity of the sample. The subject methods find use in determining the osmolarity of a sample, such as a biological sample (e.g., a tear fluid), and in the diagnosis and/or monitoring of various diseases and disorders, such as, e.g., dry eye disease.

Abstract: Optical sensors, systems and methods of use thereof are provided. Aspects of the subject systems include a sensor having a sensing surface and a configuration that directs a first optical signal to interact with the sensing surface at a first incident angle, and directs a second optical signal to interact with the sensing surface at a second incident angle. The subject sensors, systems and methods find use, e.g., in the diagnosis of dry eye disease.

Abstract: Systems and methods for determining the osmolarity of a sample are provided. Aspects of the subject methods include contacting a sensing surface of a surface plasmon resonance based sensor with a sample, and generating one or more data sets at at least two wavelengths over a time interval, wherein the data sets are used to determine the osmolarity of the sample. The subject methods find use in determining the osmolarity of a sample, such as a biological sample (e.g., a tear fluid), and in the diagnosis and/or monitoring of various diseases and disorders, such as, e.g., dry eye disease.

Abstract: An SPR detection apparatus has an optical system with a sensor member including a planar metallic layer, the sensor member being removably mountable to a housing. First optics direct an incident beam toward a rear side of the metallic layer at a predetermined range of angles to a normal to the sensor layer. Second optics guide at least one reflected beam, corresponding to the incident beam, from the metallic layer to the transducer. The transducer converts incoming electromagnetic radiation to an electrical signal for transmission to a signal processor disposed in the housing and operatively connected to the at least one opto-electrical transducer so as to detect a surface plasmon resonance angle. The first optics are configured so that the at least one incident beam spans at least about 20°.

Abstract: Optical sensors, systems and methods of use thereof are provided. Aspects of the subject systems include a sensor having a sensing surface and a configuration that directs a first optical signal to interact with the sensing surface at a first incident angle, and directs a second optical signal to interact with the sensing surface at a second incident angle. The subject sensors, systems and methods find use, e.g., in the diagnosis of dry eye disease.

Abstract: Systems and methods for determining the osmolarity of a sample are provided. Aspects of the subject methods include contacting a sensing surface of a surface plasmon resonance based sensor with a sample, and generating one or more data sets at at least two wavelengths over a time interval, wherein the data sets are used to determine the osmolarity of the sample. The subject methods find use in determining the osmolarity of a sample, such as a biological sample (e.g., a tear fluid), and in the diagnosis and/or monitoring of various diseases and disorders, such as, e.g., dry eye disease.

Abstract: A medical diagnostic method utilizes a surface plasmon resonance apparatus provided with a sensing surface. A tear sample from an eye of a patient is placed into contact with the sensing surface. The surface plasmon resonance apparatus is then operated to determine concentrations of solutes such as salt and antigenic analytes in the tear sample.