Several approaches for vitamin D determination by surface plasmon resonance and electrochemical affinity biosensors

• Published in: Biosensors & bioelectronics Vol. 40; no. 1; pp. 350 - 355
• Main Authors: Carlucci, Luciano, Favero, Gabriele, Tortolini, Cristina, Di Fusco, Massimo, Romagnoli, Elisabetta, Minisola, Salvatore, Mazzei, Franco
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 15-02-2013; Elsevier
• Subjects: 25-hydroxyvitamin D; Affinity biosensors; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Conductometry - instrumentation; Electrochemical transduction; Electrochemistry - instrumentation; Equipment Design; Equipment Failure Analysis; Fundamental and applied biological sciences. Psychology; Immunoassay - instrumentation; Methods. Procedures. Technologies; Reproducibility of Results; Sensitivity and Specificity; Surface Plasmon Resonance; Various methods and equipments; Vitamin D; Vitamin D - analysis; Surface Plasmon Resonance; Electrochemical transduction; Vitamin D; 25-hydroxyvitamin D; Affinity biosensors; Biosensor; Electrochemistry; Affinity; Resonance; Transduction; Surface plasmon
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2012.07.077

This work has been focused on the development of novel optical (Surface Plasmon Resonance) and electrochemical based biosensors for the determination of 25-OH vitamin D (25OHD) which is an important factor involved in avoiding both skeletal damage and a variety of pathological conditions, and to evaluate their potential use in clinical practice.
Different approaches to the determination of vitamin D using affinity based biosensors, are described herein; firstly, an immunosensor based on SPR transduction was realized for direct determination of vitamin D, obtaining a LOD of 2μg/ml which unfortunately is too far from the needs in clinical analysis. In order to enhance the sensitivity, the vitamin D was modified with gold nanoparticles (AuNPs): the binding of 25OHD with AuNPs determines the amplification of SPR signal, allowing to lower the LOD down to 1μg/ml, doubling the sensitivity. An alternative SPR method, based on the indirect determination of vitamin D by means of Vitamin D Binding Protein (VDBP), led to a further sensitivity increase reaching a LOD of 45ng/ml which is really close to the fixed accomplishment.
Finally, an electrochemical transduced biosensor has been realized, based on the reaction of vitamin D with 4-ferrocenylmethyl-1,2,4-triazoline-3,5-dione (FMTAD): once derivatized, the determination of 25OHD was possible in the range 20–200ng/ml with a LOD of 10ng/ml. The latter proposed system fits the requirement of determining vitamin D in a concentration range which is of significance for clinical applications; moreover, since a screen printed electrode has been used, this opens the possibility to miniaturize the sensor and developing a portable and easy-to-automate point-of-care testing device. The proposed devices provide an improvement with respect to traditional methods that are time and reagents consuming and require radioactive compounds, pretreatment procedures and expensive instrumentation.