Materials for binding per- and polyfluoroalkyl substances (PFAS) are disclosed. A fluidic device comprising the materials for detection and quantification of PFAS in a sample is disclosed. The fluidic device may be configured for multiplexed analyses. Also disclosed are methods for sorbing and remediating PFAS in a sample. The sample may be groundwater containing, or suspected of containing, one or more PFAS.

A method and a system for detecting heavy metal ions are provided. The method includes: fixing a pre-manufactured micro-electrode chip on a connecting device, connecting the connecting device to an electrochemical workstation, carrying out setting before detection on the electrochemical workstation, the micro-electrode chip including a counter electrode and a working electrode, carrying out graphene modification treatment on the counter electrode in advance, and carrying out bismuth film modification treatment on the working electrode in advance; and carrying out acid pretreatment on an aqueous solution to be detected, dropwise adding 5 .Math.L to 100 .Math.L of a treated aqueous solution to a working area of the pre-manufactured micro-electrode chip, measuring an I-V curve by the electrochemical workstation subjected to the setting before detection, and determining species and concentrations of heavy metal ions in the aqueous solution according to peak values of voltage and current of the I-V curve.

A method and a system for detecting heavy metal ions are provided. The method includes: fixing a pre-manufactured micro-electrode chip on a connecting device, connecting the connecting device to an electrochemical workstation, carrying out setting before detection on the electrochemical workstation, the micro-electrode chip including a counter electrode and a working electrode, carrying out graphene modification treatment on the counter electrode in advance, and carrying out bismuth film modification treatment on the working electrode in advance; and carrying out acid pretreatment on an aqueous solution to be detected, dropwise adding 5 .Math.L to 100 .Math.L of a treated aqueous solution to a working area of the pre-manufactured micro-electrode chip, measuring an I-V curve by the electrochemical workstation subjected to the setting before detection, and determining species and concentrations of heavy metal ions in the aqueous solution according to peak values of voltage and current of the I-V curve.

A method and sensing system for the determination per and poly-fluoroalkyl substances (PFASs) is disclosed, wherein the probe is based on measurement of the redox activity of a redox indicator. The method includes adding a PFAS compound to an indicator solution, gel, 3D printed object, electrode or a sensing surface containing and measuring the change in the indicator signal as a function of PFAS concentration. Further provided is a portable sensor for rapid monitoring of the presence and PFAS concentrations. The present invention includes deposition of the indicator component within a method, assay, apparatus and sensing platform. Further provided is a composite electrode and sensor with binding and signaling activity for a broad range of PFAS, as well as printing ink compositions that incorporate the redox indicator.

A method and sensing system for the determination per and poly-fluoroalkyl substances (PFASs) is disclosed, wherein the probe is based on measurement of the redox activity of a redox indicator. The method includes adding a PFAS compound to an indicator solution, gel, 3D printed object, electrode or a sensing surface containing and measuring the change in the indicator signal as a function of PFAS concentration. Further provided is a portable sensor for rapid monitoring of the presence and PFAS concentrations. The present invention includes deposition of the indicator component within a method, assay, apparatus and sensing platform. Further provided is a composite electrode and sensor with binding and signaling activity for a broad range of PFAS, as well as printing ink compositions that incorporate the redox indicator.

A method of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used, as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

A method of using a graphite electrode to measure a concentration of glucose or methionine from a biological sample is described. A mechanical pencil lead may be used, as the graphite electrode, and the biological sample may come from a patient's serum. The glucose or methionine may produce a peak current response within a range of 0.4-0.8 V when the sample is subjected to linear scan voltammetry.

A method for manufacturing modified metal nanoparticles includes steps as follows. Metal nanoparticles are provided, wherein each of the metal nanoparticles is a gold nanoparticle or a silver nanoparticle. An ascorbic acid solution is provided, wherein the ascorbic acid solution includes ascorbic acid molecules and/or ascorbic acid ions. A surface modification step is conducted, wherein the metal nanoparticles and the ascorbic acid solution are mixed, such that surfaces of the metal nanoparticles are modified by the ascorbic acid molecules and/or ascorbic acid ions to obtain the modified metal nanoparticles.

A source of formaldehyde for methylating a primary or secondary amine is part of an electrochemical measurement. The source of formaldehyde may be an adduct of formaldehyde.

A source of formaldehyde for methylating a primary or secondary amine is part of an electrochemical measurement. The source of formaldehyde may be an adduct of formaldehyde.