Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt-Si thin film with medium-energy neon ions at constant fluence (1.0 x 10(17) ions/cm(2)). Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (S-e/S-n) from 1 to 10. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). A TEM image of a cross section of the film irradiated with S-e/S-n = 1 shows approximate to 5 nm Pt NPs were buried up to approximate to 240 nm into the silicon. No silicide phase was detected in the XRD pattern of the film irradiated at the highest value of S-e/S-n. The synergistic effect of the energy losses of the ion beam (molten zones are produced by S-e, and sputtering and local defects are produced by S-n) leading to the synthesis and burrowing of Pt NPs is evidenced. The Pt NP synthesis mechanism and their burrowing into the silicon is discussed in detail

AFM and photoluminescence studies of swift heavy ion induced nanostructured aluminum oxide thin films

E-beam evaporated aluminum oxide films were irradiated with 120 MeV swift {Au^{9+}} ions in order to induced nanostructure formation. Atomic force microscope (AFM)results showed the formation of nanostructures for films irradiated with a fluence of $1 \times 10^{13}$ ions $cm^{-2}$. The particle size estimated by section analysis of the irradiated film was in the range 25–30 nm. Glancing angle X-ray diffraction (GAXRD) revealed the amorphous nature of the films. Two strong Photoluminescence (PL) emission bands with peaks at \sim 430 nm and \sim 645 nm besides a shoulder at \sim 540 nm were observed in all irradiated samples. The PL intensity is found to increase with increase of ion fluence

Microfluidic Affinity Sensor Based on a Molecularly Imprinted Polymer for Ultrasensitive Detection of Chlorpyrifos

The persistent use of pesticides in the agriculture field remains a serious issue related to public health. In the present work, molecularly imprinted polymer thin films were developed using electropolymerization of pyrrole (py) onto gold microelectrodes followed by electrodeposition for the selective detection of chlorpyrifos (CPF). The molecularly imprinted polymer (MIP) was synthesized by the electrochemical deposition method, which allowed in-line transfer of MIP on gold microelectrodes without using any additional adhering agents. Various parameters such as pH, monomer ratio, scan rate, and deposition cycle were optimized for sensor fabrication. The sensor was characterized at every stage of fabrication using various spectroscopic, microscopic, and electrochemical techniques. The sensor requires only 2 μL of the analyte and its linear detection range was found to be 1 μM to 1 fM. The developed sensor’s limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.93 and 2.82 fM, respectively, with a sensitivity of 3.98 (μA/(μM)/ mm2. The sensor’s shelf life was tested for 70 days. The applicability of the sensor in detecting CPF in fruit and vegetable samples was also assessed out with recovery % between 91 and 97% (RSD < 5%). The developed sensor possesses a huge commercial potential for on-field monitoring of pesticides

Investigating ripple pattern formation and damage profiles in Si and Ge induced by 100 keV Ar+ ion beam: a comparative study

Desired modifications of surfaces at the nanoscale may be achieved using energetic ion beams. In the present work, a complete study of self-assembled ripple pattern fabrication on Si and Ge by 100 keV Ar+ ion beam bombardment is discussed. The irradiation was performed in the ion fluence range of ≈3 × 1017 to 9 × 1017 ions/cm2 and at an incident angle of θ ≈ 60° with respect to the surface normal. The investigation focuses on topographical studies of pattern formation using atomic force microscopy, and induced damage profiles inside Si and Ge by Rutherford backscattering spectrometry and transmission electron microscopy. The ripple wavelength was found to scale with ion fluence, and energetic ions created more defects inside Si as compared to that of Ge. Although earlier reports suggested that Ge is resistant to structural changes upon Ar+ ion irradiation, in the present case, a ripple pattern is observed on both Si and Ge. The irradiated Si and Ge targets clearly show visible damage peaks between channel numbers (1000–1100) for Si and (1500–1600) for Ge. The clustering of defects leads to a subsequent increase of the damage peak in irradiated samples (for an ion fluence of ≈9 × 1017 ions/cm2) compared to that in unirradiated samples