Oligonucleotic Probes and Immunosensors Based on Nanoporous Anodic Alumina for Screening of Diseases

Abstract

This paper is an overview of the recent advances in nanoporous anodic alumina sensing platforms based on the interaction of oligonucleotides and antibodies with bioelements (e.g., virus, bacteria, or biomarkers) that can cause or identify diseases. Nanoporous alumina is the common platform material for all these sensing devices that have an enormous potential for the next-generation bioanalytical systems. Nanoporous alumina is a cost-effective material with morphological flexibility that provides high sensitivity to the sensing systems due to its large surface-to-volume ratio. Immunosensors transduce the signal produced by the specific antibody–antigen interaction. They are widely used for clinical analysis due to the high selectivity and sensitivity of their immunoreaction, transduced by different methods (electrochemical, optical, piezoelectric, etc). Another important, outstanding and more recently type of biosensors are based on the oligonucleotic functionalization of nanoporous alumina. Oligonucleotides can bind to a wide variety of elements (small organic molecules, proteins, or cells) with high selectivity, specificity, and affinity, even higher to those of antibodies. The basic concepts and mechanisms of their sensing methods for health care biosensing are introduced. Their transduction methods and great potential applications will be evaluated and classified in detail, together with a discussion of possible future trends.