Improved Performance of Aminopropylsilatrane Over Aminopropyltriethoxysilane as an Adhesive Film for Anchoring Gold Nanoparticles on Silicon Surfaces

Abstract

Aminopropylsilatrane (AP-silatrane) was investigated as an adhesive layer for anchoring Au nanoparticles on silicon substrates. We compared the preparation procedure and film quality of the AP-silatrane films to those of 3-aminopropyltriethoxysilane (APTES), which is commonly used for nanoparticle attachment on silicon. The films were characterized by Fourier Transform infrared (FTIR) spectroscopy, contact angle measurements, and atomic force microscopy (AFM). The process for preparing the AP-silatrane films was much easier and resulted in more reproducibly high quality films due to its insensitivity to water. In surface roughness measurements, we observed a 39% increase (99 pm RMS) for the AP-silatrane film over that of a plasma-cleaned silicon sample (71 pm RMS). In contrast, we observed a 218% increase (226 pm RMS) for the APTES film. The much higher roughness observed for the APTES film was due to its sensitivity to water, which results in molecular aggregate formation and polymerization. Gold nanoparticles (7.5 nm) were deposited and firmly anchored to both types of film surfaces. The measured height of the particles on the films was less than the actual size of the particles, and plasma treatment was used to remove the organic layer, resulting in a corrected measurement of the particle size. AP-silatrane offers an easy preparation procedure that creates a smooth, aggregate-free adhesive layer for anchoring Au nanoparticles strongly to silicon substrates.

Imaging of nucleic acids with atomic force microscopy

“…During time-lapse AFM imaging in aqueous solution, rather large aggregates appeared on the surface, presumably due to the hydrolysis of APTES molecules and their fast aggregation. These observations suggest that in addition to covalent binding of APTES, molecules adsorb loosely to the surface and form aggregates after hydrolysis [64]. …”

Label-Free Glucose Detection Using Cantilever Sensor Technology Based on Gravimetric Detection Principles

“…[13]. Con A, from Canavalia ensiformis (Jack bean) (type VI, lyophilized power, MW 26.5 kDa), was purchased from Sigma-Aldrich (USA) and was used to prepare a 1000 ppm Con A solution.…”

“…Following this procedure, alkylsilane molecules were chemically attached to the AFM tip, much like self-assembled monolayers on silicon substrates from our previous study [13]. We then put the APS-coated cantilever into a 1000 ppm Con A solution for 15 min, removed and rinsed thoroughly with milli-Q water, and then dried under a stream of pure nitrogen gas.…”

New atranes and similar ionic complexes. Synthesis, structure, properties

“…Hydrometallatrane [2 N(CН 2 СН 2 ОН) 3 Zn] 2+ . ( − OOCCH 2 OC 6 H 4 ‐Me‐2) 2 was prepared by the previously unknown (for HMA) exchange reaction of Cl − anions with anions of 2‐methyl‐phenoxyacetic acid − OOCСH 2 OC 6 Н 4 ‐Me‐2 (Scheme ) …”