Current Trends in Nanoporous Anodized Alumina Platforms for Biosensing Applications

Abstract

Pristine aluminum (Al) has received great deal of attention on fabrication of nanoporous anodized alumina (NAA) with arrays of nanosized uniform pores with controllable pore sizes and lengths by the anodization process. There are many applications of NAA in the field of biosensors due to its numerous key factors such as ease of fabrication, high surface area, chemical stability and detection of biomolecules through bioconjugation of active molecules, its rapidness, and real-time monitoring. Herein, we reviewed the recent trends on the fabrication of NAA for high sensitive biosensor platforms like bare sensors, gold coated sensors, multilayer sensors, and microfluidic device supported sensors for the detection of various biomolecules. In addition, we have discussed the future prospectus about the improvement of NAA based biosensors for the detection of biomolecules.

Electrochemical Impedance Spectroscopy (EIS): Principles, Construction, and Biosensing Applications

“…Anodic aluminum oxide nano-porous membranes are the most popular nanochannel-based platforms used with EIS technique [ 101 ]. The preparation of anodic aluminum oxide nano-porous membranes was performed by using electrochemical anodization, and they present an attractive method to develop nanopore biosensing devices due to their uniform pore size, high surface area, high aspect ratio, and inexpensive preparation [ 102 ].…”

Solid-State Nanopore for Molecular Detection

“…Depending on experimental requirements, the diameter ranging from sub-nanometer to hundreds of nanometers of the nanopore can be controlled. A number of tools are available to fabricate the nanopore with controllable accuracy including focused electron beam/focused ion-beam (FEB/FIB) [21,47,48], controlled dielectric breakdown (CDB) [49][50][51], ion track etching [52], photochemical etching [53], anodization [54], thermal annealing [55,56] and laser pulled nanopipette [57][58][59]. Figure 2 summarizes the representative nanopore fabrication procedure.…”

Effect of Negative Current on the Microstructure of Oxide Coatings Prepared by Hybrid Pulse Anodization

“…Due to that, the coating growth rate was determined by an intense competition between the formation and dissolution of coatings, which proceeded simultaneously. The two inverse processes could be expressed in formulas (1) and (2), respectively [31]. The higher negative current density caused more H + to move toward the coating/electrolyte interface under the action of an external electric field, thus accelerating the dissolution of the HPA coatings and ultimately leading to a decrease in the growth rate of the coatings.…”

“…In the past decades, porous anodic alumina (PAA) has attracted great attention as templates to produce different kinds of functional nanostructures such as nanowires and nanotubes [1]. It has been in widespread use in biological sensors [2], membrane reactors [3], energy storage devices [4], and super capacitors [5] for the regular and controllable nanopores. Most PAA coatings were fabricated using direct-current anodization (DCA) at potentiostatic mode in sulfuric acid (H 2 SO 4 ) [6,7], oxalic acid (H 2 C 2 O 4 ) [8][9][10], phosphoric acid (H 3 PO 4 ) [11], chromic acid (H 2 CrO 4 ) [12], and mixed acid electrolytes [13,14].…”