Platinum nanoparticles incorporated in silsesquioxane for use in LbL films for the simultaneous detection of dopamine and ascorbic acid
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We describe the preparation of platinum nanoparticles (PtNPs) using the 3-n-propylpyridinium silsesquioxane chloride (SiPy+Cl−) as a nanoreactor and stabilizer. The formation of PtNPs was monitored by UV–Vis spectroscopy by measuring the decrease in the intensity of the band at 375 nm, which is attributed to the electronic absorption of PtCl6 2− ions. TEM images of Pt-SiPy+Cl− nanohybrid indicated an average size of 3–40 nm for PtNPs. The Pt-SiPy+Cl− was used as a polycation in the preparation of layer-by-layer films (LbL) on a glass substrate coated with fluorine-doped tin oxide (FTO) alternating with the polyanion poly(vinyl sulfonic acid) (PVS). The films were electrochemically tested in sulfuric acid to confirm the deposition of Pt-SiPy+Cl− onto the LbL films, observing the adsorption and desorption of hydrogen (E pa = 0.1 V) and by the redox process of formation for PtO with E pa = 1.3 V and E pc = 0.65 V. FTIR and Raman spectra confirmed the presence of the PVS and Pt-SiPy+Cl− in the LbL films. A linear increase in the absorbance in the UV–Vis spectra of the Pt-SiPy+Cl− at 258 nm (π → π* transition of the pyridine groups) with a number of Pt-SiPy+Cl−/PVS or PVS/SiPy+Cl− bilayers (R = 0.992) was observed. These LbL films were tested for the determination of dopamine (DA) in the presence of ascorbic acid (AA) with a detection limit (DL) on the order of 2.6 × 10−6 mol L−1 and a quantification limit (QL) of 8.6 × 10−6 mol L−1. The films exhibited a good repeatability and reproducibility, providing a potential difference of 550 mV for the oxidation of DA with AA interferent.
KeywordsSilsesquioxane polymer Platinum nanoparticles LbL films Dopamine and ascorbic acid
The authors wish to thank CNPq and INEO (Brazil) for their financial support of this work.
- Dollish FR, Fateley WG, Bentley FF (1974) Characteristic Raman frequencies of organic compounds. Wiley-Interscience, New YorkGoogle Scholar
- Jesus CG, dos Santos V, Canestraro CD, Zucolotto V, Fujiwara ST, Gushikem Y, Wohnrath K, Pessoa CA (2011b) Silsesquioxane as a new building block material for modified electrodes fabrication and application as neurotransmitters sensors. J Nanosci Nanotechnol 11:3499–3508. doi: 10.1166/jnn.2011.3733 CrossRefGoogle Scholar
- Montenegro MCBSM, Sales MGF (2000) Flow-injection analysis of dopamine in injections with a periodate-selective electrode. J Pharm Sci 89:876–884. doi: 10.1002/1520-6017(200007)89:7<876:AID-JPS4>3.0.CO;2-R CrossRefGoogle Scholar
- Shankar SS, Swamy BEK, Chandra U, Manjunatha JG, Sherigara BS (2009) Simultaneous determination of dopamine, uric acid and ascorbic acid with CTAB modified carbon paste electrode. Int J Electrochem Sci 4:592–601Google Scholar
- Ticianelli EA, Gonzalez ER (1998) Eletroquímica. Edusp, São PauloGoogle Scholar
- Wang P, Li Y, Huang X, Wang L (2007) Fabrication of layer-by-layer modified multilayer films containing choline and gold nanoparticles and its sensing application for electrochemical determination of dopamine and uric acid. Talanta 73:431–437. doi: 10.1016/j.talanta.2007.04.022 CrossRefGoogle Scholar
- Zhuang Z, Li J, Xu R, Xiao D (2011) Electrochemical detection of dopamine in the presence of ascorbic acid using overoxidized polypyrrole/graphene modified electrodes. Int J Electrochem Sci 6:2149–2161Google Scholar