title: An InN/InGaN quantum dot electrochemical biosensor for clinical diagnosis.
abstract: Low-dimensional InN/InGaN quantum dots (QDs) are demonstrated for realizing highly sensitive and efficient potentiometric biosensors owing to their unique electronic properties. The InN QDs are biochemically functionalized. The fabricated biosensor exhibits high sensitivity of 97 mV/decade with fast output response within two seconds for the detection of cholesterol in the logarithmic concentration range of 1 × 10⁻⁶ M to 1 × 10⁻³ M. The selectivity and reusability of the biosensor are excellent and it shows negligible response to common interferents such as uric acid and ascorbic acid. We also compare the biosensing properties of the InN QDs with those of an InN thin film having the same surface properties, i.e., high density of surface donor states, but different morphology and electronic properties. The sensitivity of the InN QDs-based biosensor is twice that of the InN thin film-based biosensor, the EMF is three times larger, and the response time is five times shorter. A bare InGaN layer does not produce a stable response. Hence, the superior biosensing properties of the InN QDs are governed by their unique surface properties together with the zero-dimensional electronic properties. Altogether, the InN QDs-based biosensor reveals great potential for clinical diagnosis applications.
authors.affiliation: ISOM Institute for Systems based on Optoelectronics and Microtechnology, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain. nhalvi@isom.upm.es.
authors.forename: Naveed ul Hassan
authors.initials: Nu
authors.lastname: Alvi
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Gómez
authors.forename: Paul E D
authors.initials: PE
authors.lastname: Soto Rodriguez
authors.forename: Praveen
authors.initials: P
authors.lastname: Kumar
authors.forename: Saima
authors.initials: S
authors.lastname: Zaman
authors.forename: Magnus
authors.initials: M
authors.lastname: Willander
authors.forename: Richard
authors.initials: R
authors.lastname: Nötzel
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002784:Cholesterol / Q000032:analysis*; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007204:Indium; C473348:gallium nitride; D002784:Cholesterol; D005708:Gallium; C513701:indium nitride