77 Environmental pollution has a detrimental effect on the quality of life and ecosystems of countries with established and rapidly growing industries [1-2]. Some of the pollutants are heavy metals, which though, low in concentration, are highly toxic, of high sta- bility, and accumulate in living organisms through food chains [3- 5]. In particular, lead and cadmium are well-known severely haz- ardous metals to humans [4, 6-8]. In calcium-dependent proteins, lead occupies the binding sites for calcium which results in the impairment of physiological func- tions [9]. Excessive exposure to lead can bring health problems such as nausea, renal failure, cancer, and negative effects on me- tabolism and intelligence [10]. Heavy metals have been used as pigments in paints [11-12]. Over time, these paints degrade and chip off and become health hazards as unsuspecting people may inhale or touch them [13]. The World Health Organization has set a guideline value of 10μg/L for lead and 3μg/L for cadmium [14- 15]. The World Health Organization [16], set the limit of detection (LOD) for the determination of lead in blood for the following instruments: 10μg/L for AAS, 1μg/L for anodic stripping voltam- metry (an electrochemical technique), and 0.01μg/L for ICP-MS. Research on electrochemical techniques have surged in recent years because of their promising high sensitivity, portability, low cost, ease of operation, selectivity, and lower limit of detection [6, 9]. Other methods on the other hand, are expensive, large, and complicated [4-5, 9]. Among the electrochemical techniques, stripping voltammetric analysis is a powerful method for metal ion detection as it owes its high sensitivity to the preconcentration step that is built in the process [1, 4, 7, 9, 17-18]. Electrodes are modified with Nafion® which is a perfluorosulfonated cation exchange polymer with anti- fouling capabilities, chemical inertness, and high permeability to cations [19]. Nafion, however, being an ionomer, does not conduct electrons. To abet this problem, mediators are introduced to facili- tate electron transport between the solution and the electrode sur- face. Hexaammineruthenium(III)[Ru(NH 3 ) 6 ] 3+ or RuHex is a well- known cation model [20], which has uncomplicated chemistry [21], and displays fast electron transfer [22]. It is used for the de- termination of better sensors through the improvement of electrode kinetics of bare and modified carbon nanotube electrode biosen- sors [23, 24]. Traditional electrode materials such as gold, platinum, palladi- um, and glassy carbon are relatively expensive. They can be sub- stituted with indium tin oxide (ITO) electrodes [25, 29, 31], the *To whom correspondence should be addressed: Email: Phone: Spin Coated Hexaammineruthenium(III)/Nafion/ITO electrodes for the Determination of Lead(II) and Cadmium(II) via Anodic Stripping Voltammetry Shirley T. Palisoc 1,3 , Kevin Anthony Y. Kaw 1 , Michelle T. Natividad 1,3 and Julita C. Robles 2 1 Condensed Matter Laboratory, Physics Department, De La Salle University, 2401 Taft Avenue, Manila 0922, Philippines 2 Chemistry Department, De La Salle University, 2401 Taft Avenue, Manila 0922, Philippines 3 Condensed Matter Research Unit, Center for Natural Science and Environmental Research, College of Science, De La Salle University, 2401 Taft Avenue, Manila 0922, Philippines Received: December 15, 2016, Accepted: May 03, 2017, Available online: May 30, 2017 Abstract: Hexaammineruthenium (III) [Ru(NH 3 ) 6 ] 3+ -Nafion®-isopropanol diluted films were spin coated on indium tin oxide (ITO)- coated glass substrates. The fabricated samples were used to determine the presence of lead and cadmium in solution using anodic strip- ping voltammetry (ASV). The calibration sensitivity of the electrodes for lead and cadmium were approximately equal. Detection limits of 5ppb and 4ppb were determined for lead and cadmium respectively. Real sampling tests with commercially available yellow water color yielded 0.7106 ppm of Pb with ASV. The result was verified with atomic absorption spectrometry (AAS) which yielded 0.6923ppm of Pb. Keywords: Nafion, Stripping Voltammetry, Spin Coat, Modified Electrode, RuHex Journal of New Materials for Electrochemical Systems 20, 077-082 (2017) © J. New Mat. Electrochem. Systems