title: Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip.
abstract: Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe2+) and ferric (Fe3+) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.
authors.affiliation: Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Preetha
authors.initials: P
authors.lastname: Jothimuthu
authors.affiliation: Department of Medicine, Division of Pulmonary & Critical Care Medicine, VA Palo Alto/Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Joe L
authors.initials: JL
authors.lastname: Hsu
authors.affiliation: Stanford Nanofabrication Facility, Stanford, CA, 94305 (USA).
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.affiliation: Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Mohammed
authors.initials: M
authors.lastname: Inayathullah
authors.affiliation: Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Venkata Raveendra
authors.initials: VR
authors.lastname: Pothineni
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Antony
authors.initials: A
authors.lastname: Jan
authors.affiliation: Department of Surgery, Stanford University School of Medicine, Stanford, CA, 94305 (USA).
authors.forename: Geoffrey C
authors.initials: GC
authors.lastname: Gurtner
authors.affiliation: Biomaterials and Advanced Drug Delivery Laboratory, Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Jayakumar
authors.initials: J
authors.lastname: Rajadas
authors.affiliation: Department of Medicine, Division of Pulmonary & Critical Care Medicine, VA Palo Alto/Stanford University, Stanford, CA, 94305 (USA).
authors.forename: Mark R
authors.initials: MR
authors.lastname: Nicolls
keywords: carbon nanotubes; electrochemistry; lab-on-achip; sensors; voltammetry