The present disclosure is directed to a sensing agent. The sensing agent comprises a quantum dot; and a dye moiety coupled to the quantum dot. The sensing agent is capable of sensing at least one analyte chosen from hydrogen sulfide (H.sub.2S) and bisulfide. Sensors made from the sensing agents are also disclosed.

Disclosed are polymer nanofiber sensors for detecting gas, which generates visible color change although a specific gas having a concentration of less than 1 ppm is exposed to the sensor in a short time, in which it is impossible to detect the gas using existing colorimetric sensors, through securing high surface area and porosity, and a method of the same.

Systems and methods for analyzing a gas are provided. In some embodiments, the system includes: at least one scrubber including a scrubber material that removes at least one sulfur compound from the gas to produce a scrubbed gas; at least one gas sensor in fluid communication with the at least one scrubber, the at least one gas sensor sensing at least one remaining sulfur compound in the scrubbed gas. In some embodiments, the systems and methods disclosed herein may be used to analyze individual odorants in a hydrocarbon gas such as natural gas.

Systems, devices, and methods for a gas sensor comprising one or more optical cells; a processor having addressable memory, the processor configured to: detect gas from the one or more optical cells of the gas sensor, where the detected gas is one or more of: methane, carbon dioxide, hydrogen sulfide, water, ammonia, sulfur oxides, and nitrogen; record data corresponding to the detected gas, where the recorded data comprises at least one of: an ambient temperature from a temperature sensor, an ambient pressure from a pressure sensor, an aerial vehicle telemetry, and an aerial vehicle location from a global positioning system (GPS); and generate a map of atmospheric greenhouse gas concentration on a map based on the detected gas and the recorded data.

Disclosed are systems and methods for monitoring drilling fluids in real time. One method includes circulating a drilling fluid into and out of a borehole, generating a first output signal with a first optical computing device arranged near an outlet of the borehole, the first optical computing device having a first integrated computational element configured to optically interact with the drilling fluid, receiving the first output signal with a signal processor communicably coupled to the first optical computing device, determining the concentration of a gas present in the drilling fluid at the outlet of the borehole with the signal processor and generating a resulting output signal, conveying the resulting output signal to one or more peripheral devices, and adjusting one or more drilling or completion parameters in response to the concentration of the gas present in the drilling fluid.

A system and method for a remotely deployable, off-grid system to autonomously detect, quantify, and automatically wort emissions of methane (CH.sub.4) and other gases to the atmosphere, Automated CH.sub.4 emissions detection is accomplished by the use of commercially available CH.sub.4 sensors. CH.sub.4 accuracy is maximized by simultaneously measuring, and accounting for, undesired CH.sub.4 sensor response from interfering gases such as carbon monoxide (CO) and water vapor (H.sub.2O), and undesired CH.sub.4 sensor response from ambient temperature (T) changes. Automated CH.sub.4 emissions quantification is accomplished by calculating a leak rate (mass or volume per unit time) from the measured concentration enhancements using simultaneous measurements of wind speed and direction. Automated CH emissions reporting is accomplished following transmission of measured CH.sub.4concentrations via cellular wireless, radio, or satellite link to a central cloud-based server. Remote off-grid operation is accomplished by solar, wind, or other renewable energy source(s) that charge an on-board battery. This system offers a robust, unattended, and continuous CH.sub.4 monitoring and reporting capability to permit improved accuracy and efficiency of CH.sub.4 leak detection and repair (LDAR) from sources located in remote areas without electrical power, e.g., leak detection at well pads and processing facilities in oil and gas production areas, at concentrated animal feeding operations, and other methane sources.

A detection system includes a power generation element; a first outer cover body enveloping the power generation element; a second outer cover body located between the power generation element and the first outer cover body, and enveloping the power generation element; a first space section enclosed by the first outer cover body and the second outer cover body; a second space section enclosed by the second outer cover body; and a detector that detects a gas in the first space section.

A measurement apparatus includes: a number concentration measurement device configured to measure a number concentration of particles in a air; a humidity measurement device configured to measure a humidity of the air; and a air concentration measurement device configured to measure a concentration of a specific air in the air, wherein a mass concentration of the particles in the air is calculated based on a measured number concentration, a measured humidity, a measured concentration of the specific air, and a predetermined correlation between the number concentration, the humidity, and the concentration of the specific air, and the mass concentration of the particles in the air.

A hydrogen sulfide sensor includes a substrate, a par of interdigitated electrodes disposed on the substrate, and a homogeneous polyaniline sensing film disposed on the pair of interdigitated electrodes and having electrical conductivity that depends upon a concentration of hydrogen sulfide. A method for detecting hydrogen sulfide includes for each sensor of a plurality of sensors: generating a signal if said sensor is exposed to a sample of hydrogen sulfide having density greater than or equal to a hydrogen sulfide detection threshold of said sensor, wherein the plurality of sensors has a respective plurality of hydrogen sulfide detection limits that span a detection range. A method for forming a hydrogen sulfide sensor includes dissolving a polyaniline polymer and a metal-chloride salt in an organic solvent to form a solution, and spin-coating the solution to form a homogeneous sensing film disposed on a pair of interdigitated electrodes disposed on a substrate.

Systems and methods for a treatment of chemical sensors placed in a wellbore. A method may comprise providing a chemical sensor disposed in a sensing chamber, wherein the chemical sensor is on an optical fiber installed in a wellbore; optically interrogating the chemical sensor with the optical fiber; and pumping a treatment fluid through a fluid supply line and into the sensing chamber.