Methods and apparatus for detecting an analyte using fluorinated phthalocyanines is disclosed herein. A method for detecting an analyte includes illuminating an analyte solution which contacts an electrode comprising a conductive material having a photosensitizer coupled thereto to generate a reactive oxygen species, wherein the photosensitizer is a fluorinated pthalocyanine having a metal or a non-metal center, oxidizing an analyte present in the analyte solution with the reactive oxygen species to form an oxidized analyte, and detecting a current resulting from the reduction of the oxidized analyte at the electrode.

A biosensor having somatic cells immobilized on an electrode formed from a biologically inert material for sensing transepithelial/transendothelial electrical resistance is provided. The biosensor includes a working electrode formed from gold, graphene, carbon nanotube, or alloys or combinations thereof, having somatic cells formed directly thereon. With such a configuration, a very small sample size may be used while still eliciting an electrical response in the presence of a target composition.

The described BPE-enabled device includes two separated chambers which perform detection and reporting independently. Analytical reaction of a target molecule in the analytical cell is coupled to and monitored by an electrochromic reaction in the reporting cell. The color change in the reporting cell can be determined spectrophotometrically by RGB analysis of a CCD image acquired via smartphone. This detection method provides a linear response and a low limit of detection due to the redox cycling behavior in both chambers. The BPE based electrochromic detector can be modified for sensing of multiple analytes by integrating three or more sets of detection chemistries into one single device. Multiple analytes with different concentrations can be detected within this device simultaneously. The BPE based electrochromic device can be used for metabolite detection, wherein a redox mediator can be combined with specific oxidases to form an electrochemical mediator-electrocatalyst pair that completes redox cycling reactions.

The synthesis of silver nanoparticles (AgNPs)/meso-porous silicon (PSi) nanocomposite and its effective use as efficient chemical sensor and photocatalyst are described. The PSi was prepared via a simple stain etching of Si microparticles in HF/HNO.sub.3 aqueous solution, followed by the deposition of AgNPs onto stain etched PSi by the immersion plating technique. The resultant nanocomposite is used successfully for (i) enhanced electro-oxidation and quantification of ascorbic acid (AA) on modified glassy carbon electrode and (ii) for the photo-reduction of hexavalent chromium Cr(VI) to trivalent Cr(III) under direct visible light irradiation in the presence of citric acid.

An electrochemical probe comprises a wire bundle including two or more wire electrodes made of conducting material arranged alongside each other, and insulating material surrounding the electrodes. An impedance reducing layer of metal or metal oxide nano-structures is deposited on tips of the wire electrodes at a first end of the bundle. A functionalization layer is deposited on the impedance reducing layer at the first end of the bundle. Such a probe is particularly useful for electrochemical sensing applications such as neuronal scanning.

An oxidizing gas detection method and an apparatus thereof are provided for trace oxidizing gas detection. The detection method includes the following steps. First, perform an electroreduction reaction and a photoreduction reaction simultaneously to a metal oxide in which nanoconductors are distributed. Next, stop the electroreduction reaction and the photoreduction reaction, and read a resistance of the reduced metal oxide by applying a first pulse-width modulation signal. Next, provide an oxidizing gas to the reduced metal oxide, and photo-catalyze a redox reaction between the oxidizing gas and the reduced metal oxide. Next, read a resistance of the oxidized metal oxide by applying a second pulse-width modulation signal. Next, converse a concentration of the oxidizing gas according to a ratio of the resistance of the oxidized metal oxide and the resistance of the reduced metal oxide.

Provided herein is a biosensor for detecting a target analyte in a sample comprising a first and second photoelectrode each comprising conductive substrate and photoactive material, a first and second capture probe functionalized on the first and second photoelectrode, respectively, and optionally one or more reporter moieties comprising a detectable label, wherein the first and second capture probe each, independently, provides a distance between the detectable label and the photoactive material in the presence of the target analyte, wherein intensity of detection signal dictated by the distance is generated from the first and second photoelectrode by transfer of electrons between the detectable label and the photoactive material, wherein a higher, or higher increase than in absence of sample, in the intensity of the detection signal from the first as compared to the second photoelectrode in the presence of the sample, is indicative of the presence of the target analyte.

Various samples are generated on a substrate. The samples each includes or consists of one or more analytes. In some instances, the samples are generated through the use of gels or through vapor deposition techniques. The samples are used in an instrument for screening large numbers of analytes by locating the samples between a working electrode and a counter electrode assembly. The instrument also includes one or more light sources for illuminating each of the samples. The instrument is configured to measure the photocurrent formed through a sample as a result of the illumination of the sample.

Provided herein are systems and methods for the detection, quantification, and/or monitoring of analytes in samples. The systems and methods can be used, for example, to track the deposition and electrochemical behavior of individual nanoparticles and nanoparticles clusters clusters in situ with high spatial and temporal resolution. The systems and methods can be used to track the deposition and oxidation of several hundreds to thousands of nanoparticles simultaneously and reconstruct their voltammetric curves at the single nanoparticle level.

According to one embodiment, a biosensor includes a substrate and a sensor matrix that is present in a two-dimensional region on the substrate. The sensor matrix includes a plurality of basic blocks. Each of the basic blocks includes at least three types of sensor elements.