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Arsenic is a major global threat to the ecosystem. Here we describe a highly accurate sensing platform using silica nanoparticles/graphene at the surface of aluminum interdigitated electrodes (Al IDE), able to detect trace amounts of arsenic(III) in rice grain samples. The morphology and electrical properties of fabricated Al IDEs were characterized and standardized using AFM, and SEM with EDX analyses. Micrometer scale Al IDEs were fabricated with silicon, aluminum, and oxygen as primary elements. Validation of the bare Al IDE with electrolyte fouling was performed at different pH levels. The sensing surface was stable with no electrolyte fouling at pH 7. Each chemical modification step was monitored with current–volt measurement. The surface chemical bonds were characterized by fourier transform infrared spectroscopy (FTIR) and revealed different peaks when interacting with arsenic (1600–1000 cm−1). Both silica nanoparticles and graphene presented a sensitive limit of detection as measured by slope calibration curves at 0.0000001 pg/ml, respectively. Further, linear regression was established using ΔI (A) = 3.86 E−09 log (Arsenic concentration) [g/ml] + 8.67 E−08 [A] for silica nanoparticles, whereas for graphene Y = 3.73 E−09 (Arsenic concentration) [g/ml] + 8.52 E−08 on the linear range of 0.0000001 pg/ml to 0.01 pg/ml. The R2 for silica (0.96) and that of graphene (0.94) was close to the maximum (1). Modification with silica nanoparticles was highly stable. The potential use of silica nanoparticles in the detection of arsenic in rice grain extract can be attributed to their size and stability.

This study described a “green chemistry” synthesis of titanium oxide nanoparticle (TiO2-NP) using environment-friendly reducing agents that were from Elodea canadensis. The obtained TiO2-NP has an intense surface plasmon reverberation band at ~ 250 nm with UV–visible spectroscopic investigation which showed the intactness of TiO2-NPs. The morphological behaviour of TiO2-NPs was watched beneath field-emission scanning electron microscopy and transmission electron microscopy, shown that TiO2-NPs have a spherical pattern with a normal estimate of ~ 25 nm in breadth. The occurrence of the critical elements was pinpointed by energy-dispersive X-ray spectroscopy study, which displays the predominant titanium and oxide elements. Further support with a defined morphology and size distribution was rendered by atomic force microscopy and 3D high-power microscopy analyses. X-ray powder diffraction and chosen area electron diffraction examinations affirmed that TiO2-NPs are crystal clear in macrocosm. X-ray photoelectron spectroscopy study was uncovered natural composition of the TiO2-NPs, displaying Ti 2p crested at 458.48 eV with C1s crest for the catalyst that was shaped into a C–H constitute at 284.88 eV. The O 1s spectra moreover were displayed with authoritative vitality at 532.28 eV. XRD analysis gave proportion phase as 75%:25% for anatase and rutile. DLS showed polydispersity index esteem of − 1.23, and zeta potential for green synthesized Ti2O-NPs was − 3.87 mV. A broad hydroxyl peak was identified, and prominent peaks were notified at 1631.78 cm−1 and 3454.51 cm−1 by Fourier-transform infrared spectroscopy analysis.

SiC nanomaterial (SiCNM) is known for its excellent properties and has great potential for a wide range of applications. In this article, preparation of SiCNMs from different types of graphite was performed by microwave-assisted synthesis. Different types of graphite which are graphite flake (GF) and expanded graphite (EG) were used to react with silica for the synthesis of SiCNMs in laboratory microwave furnace at 1400 °C. It was found that SiC nanowhiskers (SiCNWs) were formed when EG was used, while irregular shaped SiC nanoparticles (SiCNPs) were formed when GF was used. β-SiC appeared as the only phase in the XRD patterns for both SiCNMs formed using GF and EG. SiCNWs and SiCNPs have interplanar spacing of around 0.25 nm which is the axial direction of [111]. The difference of formation mechanism is believed to be the origin of different morphology of SiCNMs synthesized from different types of graphite.