Point-of-Care Testing of Chloramphenicol in Food Production Using Smartphone-Based Electrochemical Detector

Antibiotic abuse in food processing could threaten human health via either direct pathogen or drug-resistant infection.To curb this situation,it is of vital significance to identify trace level of antibiotics in foodstuffin a point-of-care inspection manner.Here,a smartphone-based electrochemical system was developed for the quantitation of chloramphenicol(CAP).The differential pulse voltammetric reduction of CAP was measured facilely on a piece of gold-deposited screen-printed electrode,which was docked onto a palm-sized detector with remote directives from a mobile APP of Bluetooth handshaking and digital display.Under optimal conditions,the target CAP could be determined in a range from 1 nmol/L to 5μmol/L with a detection limit of 0.25 nmol/L.Further tests on emulate samples demonstrated the miniaturized device could handle the food-screening scenarios with accuracy,convenience and quick response.

Separation of Dopamine and Epinephrine by a Novel Electrophoresis Technique with Nafion Membrane as Separation Column

A novel electrophoresis technique, in which a strip of perflurosulfonic-acid (nafion 117) membrane was used to replace the conventional separation column and liquid buffer solution within, was developed and employed to separate the mixture of dopamine and epinephrine under a low separation voltage of 100 V with quadruple pulses amperometry detection. It was showed that the so-called Nafion membrane electrophoresis could be one of very simple and easy method and has the potentiality to be used to separate and analyze some small organic biologic molecules. Key words nafion membrane - electrophoresis - electrochemical detector - dopamine - epinephrine CLC number O 657. 7 Foundation item: Support by the Foundation of Electroanalytical Chemistry Open Lab (203231510), Changchum, China.Biography: Fang Cheng (1971-), male, Lecture, Ph. D, research direction: Electroanalysis.

State of the Art in Alcohol Sensing with 2D Materials

Since the discovery of graphene,the star among new materials,there has been a surge of attention focused on the monatomic and monomolecular sheets which can be obtained by exfoliation of layered compounds.Such materials are known as two-dimensional(2D)materials and offer enormous versatility and potential.The ultimate single atom,or molecule,thickness of the 2D materials sheets provides the highest surface to weight ratio of all the nanomaterials,which opens the door to the design of more sensitive and reliable chemical sensors.The variety of properties and the possibility of tuning the chemical and surface properties of the 2D materials increase their potential as selective sensors,targeting chemical species that were previously difficult to detect.The planar structure and the mechanical flexibility of the sheets allow new sensor designs and put 2D materials at the forefront of all the candidates for wearable applications.When developing sensors for alcohol,the response time is an essential factor for many industrial and forensic applications,particularly when it comes to hand-held devices.Here,we review recent developments in the applications of 2D materials in sensing alcohols along with a study on parameters that affect the sensing capabilities.The review also discusses the strategies used to develop the sensor along with their mechanisms of sensing and provides a critique of the current limitations of 2D materials-based alcohol sensors and an outlook for the future research required to overcome the challenges.