Abstract: In an example of a selective, real-time gas sensing method, a gas sample, potentially including a specific gas molecule to be sensed, is supplied to an interface between a working electrode and an ionic liquid electrolyte. Based on at least one unique electrochemical reaction of the specific gas molecule to be sensed, a driving force is implemented to initiate a series of reactions involving the specific gas molecule. In response to the implementation of the driving force, a signal indicative of the specific gas molecule is monitored for.

Abstract: In an example of a selective, real-time gas sensing method, a gas sample, potentially including a specific gas molecule to be sensed, is supplied to an interface between a working electrode and an ionic liquid electrolyte. Based on at least one unique electrochemical reaction of the specific gas molecule to be sensed, a driving force is implemented to initiate a series of reactions involving the specific gas molecule. In response to the implementation of the driving force, a signal indicative of the specific gas molecule is monitored for.

Abstract: A multi-modal biosensor system includes a vibrating plate orientated along a plane. An actuator is interfaced with the vibrating plate and operable to vibrate the vibrating plate along the plane. The actuator includes two electrodes rigidly affixed to the vibrating plate. An optical support structure is rigidly affixed to the vibrating plate, and provides an outwardly facing surface to receive a measurement sample. A light source is configured to project light onto the outwardly facing surface of the optical support structure. A light detector is configured to capture light reflected from the outwardly facing surface of the optical support structure. A controller interfaces with the two electrodes and the light detector. The controller operates to detect changes in the vibrating motion of the vibrating plate concurrently with detecting changes in the light captured by the light detector.

Abstract: A multi-modal biosensor system includes a vibrating plate orientated along a plane. An actuator is interfaced with the vibrating plate and operable to vibrate the vibrating plate along the plane. The actuator includes two electrodes rigidly affixed to the vibrating plate. An optical support structure is rigidly affixed to the vibrating plate, and provides an outwardly facing surface to receive a measurement sample. A light source is configured to project light onto the outwardly facing surface of the optical support structure. A light detector is configured to capture light reflected from the outwardly facing surface of the optical support structure. A controller interfaces with the two electrodes and the light detector. The controller operates to detect changes in the vibrating motion of the vibrating plate concurrently with detecting changes in the light captured by the light detector.

Abstract: Real-time and end point determination of antibiotic effects are disclosed herein. In one example, a surface of a label free biosensor is exposed to a sample including a gram-negative bacteria. A frequency and/or a current of the biosensor is then allowed to reach a constant value. The surface of the biosensor is then exposed to an antibiotic. Using the biosensor, i) a frequency change versus time and a damping resistance versus time, or ii) a current versus voltage or the current versus time at a fixed potential, or iii) both i and ii are then measured. The frequency change versus time and the damping resistance versus time and/or the current versus voltage or the current versus time are correlated to determine an effect of the antibiotic on the gram-negative bacteria. Examples of the label free biosensors and methods for detecting gram-negative bacteria using the label free biosensors are also disclosed.

Abstract: In an example of a selective, real-time gas sensing method, a gas sample, potentially including a specific gas molecule to be sensed, is supplied to an interface between a working electrode and an ionic liquid electrolyte. Based on at least one unique electrochemical reaction of the specific gas molecule to be sensed, a driving force is implemented to initiate a series of reactions involving the specific gas molecule. In response to the implementation of the driving force, a signal indicative of the specific gas molecule is monitored for.

Abstract: In a method for monitoring cell-to-cell interactions, a quartz crystal microbalance surface is exposed to a medium including a first cell. The first cell is exposed to a sample including a suspect cell. The first cell is activated prior to or simultaneously with the first cell exposure. Frequency and motional resistance changes versus time are measured after each of: surface exposure to the medium, first cell activation prior to the exposure to the sample, and first cell exposure to the sample; or after each of: surface exposure to the medium and simultaneous first cell activation and sample exposure. From the frequency and motional resistance changes versus time, any of i) a level of adhesion of the suspect cell to the activated first cell, ii) a type of the suspect cell, iii) a behavior or activity of the suspect cell is determined, or iv) activation of the first cell is determined.

Abstract: Real-time and end point determination of antibiotic effects are disclosed herein. In one example, a surface of a label free biosensor is exposed to a sample including a gram-negative bacteria. A frequency and/or a current of the biosensor is then allowed to reach a constant value. The surface of the biosensor is then exposed to an antibiotic. Using the biosensor, i) a frequency change versus time and a damping resistance versus time, or ii) a current versus voltage or the current versus time at a fixed potential, or iii) both i and ii are then measured. The frequency change versus time and the damping resistance versus time and/or the current versus voltage or the current versus time are correlated to determine an effect of the antibiotic on the gram-negative bacteria. Examples of the label free biosensors and methods for detecting gram-negative bacteria using the label free biosensors are also disclosed.

Abstract: In a method for monitoring cell-to-cell interactions, a quartz crystal microbalance surface is exposed to a medium including a first cell. The first cell is exposed to a sample including a suspect cell. The first cell is activated prior to or simultaneously with the first cellexposure. Frequency and motional resistance changes versus time are measured after each of: surface exposure to the medium, first cell activation prior to the exposure to the sample, and first cell exposure to the sample; or after each of: surface exposure to the medium and simultaneous first cell activation and sample exposure. From the frequency and motional resistance changes versus time, any of i) a level of adhesion of the suspect cell to the activated first cell, ii) a type of the suspect cell, iii) a behavior or activity of the suspect cell is determined, or iv) activation of the first cell is determined.

Abstract: Methods of binding and detecting a microorganism on a solid substrate. The microorganism is bound on a solid substrate covalently bound to a capture agent having a saccharide moiety. A lectin capable of binding to the microorganism and the saccharide moiety of the capture agent is added to the sample to bind the microorganism on the solid substrate. Further provided are biosensor devices, such as a quartz crystal microbalance (QCM) device or a surface plasmon resonance (SPR) device, that incorporate the solid substrate for the detection of microorganisms.

Abstract: An alkane gas is supplied to an interface between an activated surface of a platinum or palladium working electrode and an ionic liquid electrolyte. The alkane adsorbs at or near an interface complex formed at the interface. The ionic liquid electrolyte is selected from a group consisting of 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and combinations thereof.

Abstract: An aerobic method for oxidizing an alkane is disclosed herein. At least a portion of a surface of a platinum working electrode is activated at an interface between the platinum working electrode and an ionic liquid electrolyte (i.e., 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imidem, and combinations thereof). An interface complex is formed at the interface. An alkane gas is supplied to the interface. The alkane adsorbs at or near the interface complex.

Abstract: An alkane gas is supplied to an interface between an activated surface of a platinum or palladium working electrode and an ionic liquid electrolyte. The alkane adsorbs at or near an interface complex formed at the interface. The ionic liquid electrolyte is selected from a group consisting of 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imidem, and combinations thereof.

Abstract: Methods of binding and detecting a microorganism on a solid substrate. The microorganism is bound on a solid substrate covalently bound to a capture agent having a saccharide moiety. A lectin capable of binding to the microorganism and the saccharide moiety of the capture agent is added to the sample to bind the microorganism on the solid substrate. Further provided are biosensor devices, such as a quartz crystal microbalance (QCM) device or a surface plasmon resonance (SPR) device, that incorporate the solid substrate for the detection of microorganisms.

Abstract: An aerobic method for oxidizing an alkane is disclosed herein. At least a portion of a surface of a platinum working electrode is activated at an interface between the platinum working electrode and an ionic liquid electrolyte (i.e., 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imidem, and combinations thereof). An interface complex is formed at the interface. An alkane gas is supplied to the interface. The alkane adsorbs at or near the interface complex.

Abstract: An electrochemical piezoelectric sensor is disclosed. The sensor includes a piezoelectric substrate, three (or more) electrodes over a first surface of the substrate, and another electrode over a second (opposing) surface of the substrate. An ionic liquid in the form of a film is adhered, bound, immobilized, or otherwise positioned over the substrate and electrodes of the first surface. The ionic liquid film permits the absorption and detection of analytes from a gaseous sample, for environmental gases, example explosive vapors and/or explosive vapor species in the gaseous sample. Detection (optionally including analyte quantitation and qualitative identification) can be performed by both electrochemical and piezoelectric techniques using a single sensor. Systems incorporating and methods of using the electrochemical piezoelectric sensor also are disclosed.

Abstract: An apparatus and methods for binding an analyte of interest in a sample are provided. The apparatus comprises a substrate with an exposed surface with an compound, that is electrostatically charged or capable of forming hydrogen bonds, provided bound to the solid substrate. A recombinant single chain antibody (scFv) molecule specific for the analyte of interest, having one or more amino acids with charged or hydrogen-bond forming sidechains in a linker polypeptide portion, is bound to the layer on the solid substrate. When the analyte of interest is present in the sample the scFv binds the analyte to the solid substrate. The apparatus can be used with an immunoglobulin layer to detect Fc receptors, so as to detect microorganisms such as Staphylococcus aureus having protein A or protein G.

Abstract: Methods of binding and detecting a microorganism on a solid substrate. The microorganism is bound on a solid substrate covalently bound to a capture agent having a saccharide moiety. A lectin capable of binding to the microorganism and the saccharide moiety of the capture agent is added to the sample to bind the microorganism on the solid substrate. Further provided are biosensor devices, such as a quartz crystal microbalance (QCM) device or a surface plasmon resonance (SPR) device, that incorporate the solid substrate for the detection of microorganisms.

Abstract: An apparatus and methods for binding an analyte of interest in a sample are provided. The apparatus comprises a substrate with an exposed surface with an compound, that is electrostatically charged or capable of forming hydrogen bonds, provided bound to the solid substrate. A recombinant single chain antibody (scFv) molecule specific for the analyte of interest, having one or more amino acids with charged or hydrogen-bond forming sidechains in a linker polypeptide portion, is bound to the layer on the solid substrate. When the analyte of interest is present in the sample the scFv binds the analyte to the solid substrate. The apparatus can be used with an immunoglobulin layer to detect Fc receptors, so as to detect microorganisms such as Staphylococcus aureus having protein A or protein G.

Abstract: A surface plasmon resonance biosensor device and system are provided. The simplicity of SPR biosensor design allows easy integration with both QCM and electrochemistry techniques, not found in current SPR biosensor devices. In some embodiments, the surface plasmon resonance biosensor device has a dual SPR/QCM sample holder which allows simultaneous detection by both surface plasmon resonance and also quartz crystal microbalance (QCM) techniques. In additional embodiments, the surface plasmon resonance biosensor device and/or the dual SPR/QCM technique can be integrated with electrochemistry techniques by incorporate reference and counter electrodes in the SPR or SPR/QCM sample holder. Methods of using the device and system to determine whether an analyte of interest is present in a sample are also provided.