Electrogenerated chemiluminescence from hydrophilic and hydrophobic carbon nanoparticles

GABRIELA MARZARI; M. SERGIO MORENO; GUSTAVO MORALES; FERNANDO FUNGO

Encuentro; X Encuentro Latinoamericano de Fotoquímica y Fotobiología; 2010

Electrogenerated chemiluminescence (ECL) involves the generation of charged species at electrode surfaces undergo a highly exergonic reaction to produce an electronically excited state that then emits light. ECL biosensor, combines advantages from the selectivity of the biological recognition elements and the sensitivity of ECL technique; providing a powerful tool for ultrasensitive biomolecular detection and quantification. Nanomaterials have recently attracted the interest of many researchers in the field of biosensors owing to their unique physical and chemical properties, which have led to novel biosensors that exhibit high sensitivity and stability. Most of the nanomaterials used in ECL are based on semiconductor and precious metal nanoparticles. However, they have in their composition toxic and expensive metals respectively. Recently, fluorescent carbon nanoparticles (CNPs) of low toxicity have been synthesized. Herein, we present a simple and effective method for preparing ECL hydrophilic and hydrophobic CNPs which are suitable for further surface modification. The CNPs were synthesized by thermal treatment of molecular precursors. The graphitic nature and morphology of the resulting CNPs were analyzed by transmission electron microscopy (inset Figure 1). The electronic properties of CNPs were characterized by UV-vis absorption, photoluminescence (PL), electrochemistry and ECL. The fluorescent emission peaks of CNPs are shifted to longer wavelengths with increasing excitation energy. Figure 1 show the ECL phenomenon obtained from CNPs in the presence of a coreactant (tri-n-butylamine). This preliminary work envisions promising applications into the area of biological labeling and biosensors.