Andrew Pike Research Group

Based in the Chemical Nanoscience Laboratory in the School of Chemistry, we pursue many aspects of chemistry related to DNA nanotechnology.  Our core interests lie in applying organic, inorganic and biochemical synthetic routes to develop electronically active nanostructures based on the double helix of DNA. We are also interested in the integration of DNA and conducting polymers with silicon surfaces for sensor based applications.

On these pages you can find out more about who we are and what’s going on in our laboratory, including our current and future research. Also, as the Undergraduate Admissions Tutor for all Chemistry Programmes at Newcastle University I am running a blog with the goal of helping applicants in the decision making process as they choose their course, University town and future career. Do visit and contribute to the discussion through this link, Chemistry Admissions.

Recent Research Highlights 

 

Ferrocene modified silicon showing ambipolar FET behaviour

 

As revealed for the first time by in situ scanning tunnelling spectroscopy (STS), ferrocene-modified Si(111) substrates show ambipolar field effect transistor (FET) behaviour upon electrolyte gating. This work was performed in collaboration with Prof. Thomas Wandlowski (University of Bern) and demonstrates the potential for developing molecular based memory systems from ferrocene modified silicon surfaces. In other words, applying a sufficiently positive potential to the silicon substrate transformsferrocene to ferrocenium, which is equivalent to the change of a bit of information from the ‘‘0’’ to the ‘‘1’’ state.This redox process is reversible, and as a consequence one mayerase the stored charge and return the device to its initial state.

We successfully demonstrated the doping of asilicon surface with electrochemically active ferrocene moietiescovalently attached to n-Si(111). The in situ STS study demonstrated unexpected ambipolar FET behaviour of the Si-ferrocene hybrid sample. Control experiments with electrochemicallyinert octene samples show convincingly that allenhancement effects observed in the tunnelling current response are directly related to the presence of the redoxactiveferrocene unit.<.

You can read more about this work here: Artem Mishchenko, Mufida Abdualla, Alexander Rudnev, Yongchun Fu, Andrew R. Pike and Thomas Wandlowski Chem. Commun., 2011, 47, 9807-9809

 

“Click” modification of DNA templated nanowires

 

DNA templated nanowires of a pentynyl-modified poly2-(2-thienyl)-pyrrole undergo functionalisation via “click chemistry” and retain their 1D-nanostructure and conductive properties.

This work was largely performed by Jennifer Hannant, Joe Hedley and Jonny Pate as part of their PhD and MChem research projects.

Here we report the preparation of a conducting DNA-based nanowire system that can be readily functionalised. The approach uses individual strands of DNA to template thegrowth of a conducting polymerfrom monomers of N-pentynyl-2-(2-thienyl)-pyrrole. The resulting supramolecularpolymer/DNA material is formed as nanowires which can undergo functionalisation using ‘‘click’’ chemistry. Through EFM studieswe confirm that the polymer/DNA nanowires are electrically conducting and that they remain conductive after functionalisation via the ‘‘click’’ reaction.

This methodology has potential for the development of conductive nanowires as sensing elements with a wide range of applications; the azido derivative of a receptor group is simply‘‘clicked’’ onto the nanowire sensor/transducer. Conducting polymer nanowires bring the advantage of significantly enhanced sensitivity over an electrode/polymer-film system due to the massively increased surface/volume ratio. Therefore changes in the conductivity of the polymer/DNA nanowirehybrid system described here may hold potential for use in molecular electronics or even single molecule detection.

You can read more about this work here: Jennifer Hannant, Joseph H. Hedley, Jonathan Pate, Adam Walli, Said A. Farha Al-Said, Miguel A. Galindo, Bernard A. Connolly, Benjamin R. Horrocks, Andrew Houlton and Andrew R. Pike  Chem. Commun., 2010, 46, 5870-5872