title: A smartphone platform for the quantification of vitamin D levels.
abstract: Vitamin D deficiency has been linked to a number of diseases and adverse outcomes including: osteoporosis, infections, diabetes, cardiovascular diseases, and even cancer. At present the vast majority of vitamin D testing is performed in large-scale laboratories at the request of a physician as part of an annual panel of blood tests. Here we present a system for rapid quantification of vitamin D levels on a smartphone. The system consists of a smartphone accessory, an app, and a test strip that allows the colorimetric detection of 25-hydroxyvitamin D using a novel gold nanoparticle-based immunoassay. We show that the system can be used to accurately measure physiological levels of 25-hydroxyvitamin D with accuracy better than 15 nM and a precision of 10 nM. We compare our system with well-established ELISA test kits for serum samples of unknown concentration and demonstrate equivalency of the results. We envision this as the first step towards the development of the NutriPhone, a comprehensive system for the analysis of multiple vitamins and micronutrients on a smartphone.
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA. de54@cornell.edu.
authors.forename: Seoho
authors.initials: S
authors.lastname: Lee
authors.forename: Vlad
authors.initials: V
authors.lastname: Oncescu
authors.forename: Matt
authors.initials: M
authors.lastname: Mancuso
authors.forename: Saurabh
authors.initials: S
authors.lastname: Mehta
authors.forename: David
authors.initials: D
authors.lastname: Erickson
mesh_terms: D040421:Cell Phone; D003124:Colorimetry; D004797:Enzyme-Linked Immunosorbent Assay; D006046:Gold / Q000737:chemistry; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry; D011934:Reagent Strips / Q000737:chemistry; D013499:Surface Properties; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry
chemical_list: D011934:Reagent Strips; D014807:Vitamin D; D006046:Gold; C104450:25-hydroxyvitamin D