Abstract: Provided herein are methods of detecting target molecules using electrochemical sensors that comprise biomolecular receptor-bound redox reporters. Related systems and computer readable media are also provided.

Abstract: Provided herein are methods of detecting pathogen antibodies, such as a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), in samples. Related devices, kits, reaction mixtures, and systems are also provided.

Abstract: Described herein are variations of a cortisol monitoring system, including a cortisol monitoring device. For example, a cortisol monitoring device may include a skin-penetrating microneedle array for use in measuring cortisol, such as in a continuous manner. The microneedle array may include, for example, at least one microneedle comprising a working electrode comprising a cortisol-sensing aptamer that selectively and reversibly binds to cortisol. The microneedle array may include, for example, at least one microneedle including a tapered distal portion having an insulated distal apex, and an electrode on a surface of the tapered distal portion located proximal to the insulated distal apex. At least some of the microneedles may be electrically isolated such that one or more electrodes is individually addressable.

Abstract: Improved electrochemical sensors wherein the recognition element is co-deposited with a secondary, charge transfer modulating moiety, for example an oligonucleotide. The secondary moiety modulates electron transfer kinetics to enhance the frequency dependence of sensor gain, enabling the use of kinetic differential drift correction techniques and like measurements that require a target insensitive signal drifts in parallel with target-dependent output. The secondary moiety also increases the gain and signal to noise of the sensor and can be used to enable calibration-free measurement. Accurate drift-corrected in vivo sensor use with multiple measurements of analyte concentration per minute in flowing blood is demonstrated.

Abstract: The invention encompasses novel methods of operating electrochemical sensors such as aptamer-based sensors to analyze complex samples, such as flowing whole blood both in vitro or in vivo. In such environments, electrochemical sensors are often subject to drift, which complicates the interpretation of sensor output in terms of target concentration. The method of the invention utilizes a dual-reporter recognition element that generates a first, sensing current that is responsive to target binding and to environmental factors and a second, reference current that is only affected by environmental factors. The reference current provides information about environmentally-induced drift, which allows the drift effect to be subtracted out. By removing drift artifacts, electrochemical sensors may be deployed to analyze complex samples, such as whole blood, in vivo.

Abstract: Typical electrochemical sensors measure target-induced changes in current output. Such measures of target binding are inconsistent across individual sensors, and furthermore, signal will drift over time when the sensor is deployed for long periods. These shortcomings can be avoided by the novel use of chronoamperometry to measure current decay kinetics as the indicator of target binding. Current decay lifetimes will vary in a concentration dependent manner, but remain stable across individual sensors and over time, allowing for calibration-free operation. By these methods, aptamer based electrochemical sensors and other sensor types may be deployed in vivo for extended periods of time and will provide accurate measurement of target binding without calibration.

Abstract: The invention encompasses novel sensor designs that can operate in complex samples like whole blood. The use of protective filtering membranes prevents fouling and erroneous signal drift in sensors such as aptamer based electrochemical sensors. In one aspect, the invention encompasses implantable sensors that can be deployed to the circulatory system of an animal where they can accurately and continuously measure the concentration of a target species, such as a drug, with very short resolution times, for extended periods without signal drift. These sensor designs and associated methods provide a means of accurately dosing animals based on real-time monitoring of drugs and other chemical markers and biomarkers.

Abstract: A redox flow battery that uses metal complexes with amino-alcohol ligands as the electroactive species in alkaline electrolytes to store electrical energy. The battery includes a first and a second electrolyte storage unit that each includes a metal complex selected from transition metals with an amino-alcohol ligand as an electroactive species in an alkaline electrolyte. Such solutions in these electrolyte storage units are each prepared by mixing stoichiometric amounts of a metal ion and an amino-alcohol ligand in water to form a metal-ligand mixture followed by adding an amount corresponding to 3-5 moles/liter of an alkaline electrolyte solution to each metal-ligand mixture to form a metal complex with the amino-alcohol ligand in the alkaline electrolyte to be used by a storage unit. As a result, the operational and maintenance costs of the redox flow battery are reduced while reducing the complexity of the manufacturing process.

Abstract: A redox flow battery that uses metal complexes with amino-alcohol ligands as the electroactive species in alkaline electrolytes to store electrical energy. The battery includes a first and a second electrolyte storage unit that each includes a metal complex selected from transition metals with an amino-alcohol ligand as an electroactive species in an alkaline electrolyte. Such solutions in these electrolyte storage units are each prepared by mixing stoichiometric amounts of a metal ion and an amino-alcohol ligand in water to form a metal-ligand mixture followed by adding an amount corresponding to 3-5 moles/liter of an alkaline electrolyte solution to each metal-ligand mixture to form a metal complex with the amino-alcohol ligand in the alkaline electrolyte to be used by a storage unit. As a result, the operational and maintenance costs of the redox flow battery are reduced while reducing the complexity of the manufacturing process.