A Highly Efficient Sensor Platform Using Simply Manufactured Nanodot Patterned Substrates.

Sozaraj Rasappa,Michael A Morris,Tandra Ghoshal,Justin D Holmes,Ramsankar Senthamaraikannan,Dipu Borah

doi:10.1038/srep13270

Abstract

Block copolymer (BCP) self-assembly is a low-cost means to nanopattern surfaces. Here, we use these nanopatterns to directly print arrays of nanodots onto a conducting substrate (Indium Tin Oxide (ITO) coated glass) for application as an electrochemical sensor for ethanol (EtOH) and hydrogen peroxide (H2O2) detection. The work demonstrates that BCP systems can be used as a highly efficient, flexible methodology for creating functional surfaces of materials. Highly dense iron oxide nanodots arrays that mimicked the original BCP pattern were prepared by an ‘insitu’ BCP inclusion methodology using poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO). The electrochemical behaviour of these densely packed arrays of iron oxide nanodots fabricated by two different molecular weight PS-b-PEO systems was studied. The dual detection of EtOH and H2O2 was clearly observed. The as-prepared nanodots have good long term thermal and chemical stability at the substrate and demonstrate promising electrocatalytic performance.

Highlights

Electrochemical sensors offer elegant routes for interfacing, at the molecular level, chemical or biological recognition events and electronic signal-transduction processes for meeting the size, cost, low-volume and power requirements of decentralized testing and are highly promising candidates in a wide range of biomedical or environmental applications[1,2,3,4,5]
To the best of our knowledge, this is the first demonstration of this methodology for the single and dual detection of EtOH and H2O2 which illustrates the capability of these technique
The annealing process depends on a combination of two major effects: (1) PEO has a higher surface tension (γ C = 43 mNm−1) than PS (γ C = 33 mNm−1) that would lead to preferential PS surface segregation; (2) this may be compensated by the fact that the annealing solvent is toluene, δ Hildebrand ∫ δ H = 18.2 (MPa)1⁄2, which is a preferential solvent for PS, δ H = 18.7 (MPa)1⁄2, over PEO, δ H = 20.3 (MPa)1⁄2

Summary

Introduction

Electrochemical sensors offer elegant routes for interfacing, at the molecular level, chemical or biological recognition events and electronic signal-transduction processes for meeting the size, cost, low-volume and power requirements of decentralized testing and are highly promising candidates in a wide range of biomedical or environmental applications[1,2,3,4,5]. The low-cost fabrication of highly efficient electrochemical nanoengineered sensors of high reproducibility and stability is a challenge[6]. Metal/metal oxide nanoparticles and nanocomposites immobilized on a working electrode surface have attracted substantial interest as sensing elements because of their high surface area and can be formed via a range of methods including physical adsorption, chemical covalent bonding, electrodeposition, electropolymerization and so on[10,11,12]. We have used our established methodology for silicon substrates[22] to produce ordered iron oxide nanopatterns on ITO. These well-defined arrays were used for the electrochemical sensing of EtOH and H2O2 and their performance quantified in terms of their density, stability and sensitivity. To the best of our knowledge, this is the first demonstration of this methodology for the single and dual detection of EtOH and H2O2 which illustrates the capability of these technique

Methods

Results

Conclusion