Sensors and Actuators B 176 (2013) 768–774 Contents lists available at SciVerse ScienceDirect Sensors and Actuators B: Chemical journa l h o me pa ge: www.elsevier.com/locate/snb Novel fully screen printed flexible electrochemical sensor for the investigation of electron transfer between thiol functionalized viologen and gold clusters Binu Baby Narakathu a,∗ , Mary Sajini Devadas b,d , Avuthu Sai Guruva Reddy a , Ali Eshkeiti a , Akhil Moorthi a , Isurika R. Fernando b , Bazsa P. Miller b , Guda Ramakrishna b , Ekkehard Sinn b , Margaret Joyce c , Marian Rebros c , Erika Rebrosova c , Gellert Mezei b,∗∗ , Massood Zandi Atashbar a a Department of Electrical and Computer Engineering, Western Michigan University, MI 49008, USA b Department of Chemistry, Western Michigan University, MI 49008, USA c Department of Paper Engineering, Chemical Engineering and Imaging, Western Michigan University, MI 49008, USA d Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA a r t i c l e i n f o Article history: Received 25 July 2012 Received in revised form 26 September 2012 Accepted 13 October 2012 Available online 22 October 2012 Keywords: Electrochemical sensor Flexible sensor Gold clusters Screen printing Viologen a b s t r a c t A novel electrochemical sensor was fabricated for the investigation of the effect of electron transfer between glutathione (GS) protected gold nanoparticles (AuNPs) and a new C 4 -thiol functionalized violo- gen axle molecule (V 2+ -SH) on pseudorotaxane formation. The sensor was fully screen printed with silver (Ag) ink on a flexible polyethylene terephthalate (PET) substrate. Square wave voltammetry (SQWV) based response of the sensor toward V 2+ -SH in the presence of Au 25 or 4 nm-Au demonstrated one- electron transfer processes, based on 59 mV changes in peak potentials to more negative values. The response demonstrated the capability of the novel electrochemical sensor to be used for studying complex systems in volumes as small as 5–10 L, with less sample preparation time. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Printed electronics (PE), a rapidly emerging and relatively new technology within the electronics industry, has been generating an enormous research and development (R&D) and commercial potential across the semiconductor industries. Significant advance- ments in the development of organic and polymeric electronic materials have opened up a vast potential for commercially viable PE devices. PE leverages the prospect of employing traditional printing methods such as offset, rotogravure, inkjet and screen printing techniques by significantly simplifying the manufacturing environment and fabrication steps, when compared to conven- tional silicon (Si) technology which involves high-vacuum and high-temperature deposition processes along with sophisticated photolithographic patterning techniques [1]. The feasibility of ∗ Corresponding author at: 4601 Campus Drive, Western Michigan University, Department of Electrical and Computer Engineering, Kalamazoo, MI 49008, USA. Tel.: +1 269 779 0445. ∗∗ Corresponding author at: 1903 W Michigan Ave, Western Michigan University, Department of Chemistry, Kalamazoo, MI 49008, USA. Tel: +1 269 387 2859. E-mail addresses: binubaby.narakathu@wmich.edu (B.B. Narakathu), gellert.mezei@wmich.edu (G. Mezei). “roll-to-roll” (R2R) production along with the efficient usage of resources during fabrication and mechanical stability of printed electronic devices makes them potential candidates for cost effi- cient, flexible and lightweight products. Research in the field of PE has resulted in the development of devices for applications such as electronic paper [2], radio-frequency identification (RFID) tags [3,4], organic light-emitting diodes (OLEDs) [5,6], organic thin film transistors (OTFT) [7,8], and low-cost photovoltaics (OPV) [9,10]. However, there are relatively few reports on fully screen printed electrochemical sensing devices. The development of efficient, miniaturized, rapid and easy- use electrochemical sensors for use in portable and field-usable biochemical microsensing systems has been widely researched for applications in the biomedical, environmental and defense industries [11–13]. The advancements made possible in tradi- tional printing techniques, with respect to a diverse nature of manufacturing materials, functional inks and highly sophisticated printers, provides a promising potential for the miniaturization and development of highly sensitive and selective electrochemical sensors. The main advantage associated with the miniaturization of the electrochemical sensors is the reduction of sample volume required, to as low as a few microliters, which in turn helps in reducing the overall size of the diagnostic system into which the device will be integrated. Miniaturization of the sensor device is 0925-4005/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.snb.2012.10.069