Dalam kajian ini, nanopartikel emas 40 nm (AuNPs) telah disintesis dengan menggunakan kaedah pertumbuhan pembiakan. AuNP disintesis dicirikan dengan menggunakan analisis Zeta-sizer, Spektrofotometer Inframerah Jarak Jauh (UV-Vis), X-ray Diffractometer (XRD), Transmisi Elektron Mikroskopi (TEM). Indium timah oksida pada kaca (ITO) substrat digunakan untuk fabrikasi elektrod yang diubah suai. Penyelesaian AuNPs digunakan untuk berkumpul sendiri dengan bantuan Aminopropyltriethoxysilane (APTES) pada elektrod ITO untuk pengesanan elektrokimia Pb (II) dan Hg (II). APTES bertindak sebagai penyambung antara elektrod ITO dan AuNPs. Beberapa parameter telah disiasat iaitu: kepekatan konsentrasi APTES dan kesan perendaman dalam AuNPs. Elektrod diubahsuai AuNPs / APTES / ITO tertakluk kepada voltammetrik kitaran (CV) dan analisa Voltammetry (DPASV) Pulse Differential Pulse. Analisa CV digunakan untuk mengkaji tingkah laku elektrokimia manakala DPASV dilakukan pada setiap parameter untuk mendapatkan nilai terendah pengesanan (LOD) Pb (II) dan Hg (II). Analisis emisi Mikroskop Pengimbasan Pelepasan Medan (FESEM) dan Mikroskop Dispersif Tenaga (EDX) digunakan untuk memerhatikan morfologi elektrod AuNPs / APTES / ITO. Kepekatan APTES yang optimum adalah 0.5% daripada kepekatan APTES dengan masa merendam optimum selama 2 jam di AuNPs untuk pembentukan elektrod yang diubahsuai AuNPs / APTES / ITO. Elektrod yang diubahsuai menunjukkan nilai LOD 1.18 μg / L untuk Pb (II) dan 0.38μg / L untuk Hg (II).
_______________________________________________________________________________________________________
In this study, 40 nm gold nanoparticles (AuNPs) were synthesized by using seeded-growth method. The synthesized AuNPs were characterized using Zetasizer analysis, UV- Visible Near-Infrared Spectrophotometer, X-ray Diffractometer (XRD), Transmission Electron Microscopy (TEM). Indium tin oxide on glass (ITO) substrates were used for fabrication of modified electrodes. The AuNPs solutions were used to self-assembled with the aid of Aminopropyltriethoxysilane (APTES) on ITO electrode for the electrochemical detections of Pb(II) and Hg(II). APTES acted as a linker between ITO electrode and AuNPs. Several parameters were investigated which were: effects of APTES concentration(0.3%, 0.5%, 0.75%, 1%) and effect of soaking period(1 hour, 1.5 hour, 2 hour, 2.5 hour) in AuNPs. The AuNPs/APTES/ITO modified electrode were subjected to cyclic voltammetry (CV) and Differential Pulse Anodic Stripping Voltammetry (DPASV) analyses. CV analysis was used to study the electrochemical behaviour while DPASV was performed on each parameters to find the lowest value of limit of detection (LOD) of Pb(II) and Hg(II). Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive Microscope (EDX) analysis were used to observe the morphology of AuNPs/APTES/ITO electrodes. Optimum APTES concentration was 0.5% of APTES concentration with optimum soaking time of 2 hour soaking period in AuNPs for formation of the AuNPs/APTES/ITO modified electrode.The modified electrode showed LOD value 1.18 μg/L for Pb(II) and 0.38μg/L for Hg(II).
Self assembly of gold nanoparticles modified electrode for Pb and Hg detection / Siti Nasirah Nasrul