a
Nanotechnology and Integrated Bio-Engineering Centre, NIBEC, School of Engineering, University of Ulster, Newtownabbey, UK
E-mail: p.papakonstantinou@ulster.ac.uk
b
College of Chemistry and Molecular Engineering, Peking University, Beijing, P.R. China
c
School of Electrical Engineering, Queen's University of Belfast, Belfast, UK
d
Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland
e
School of Chemistry, University of St Andrews, St Andrews, Scotland, UK