Silica/CdTe/silica fluorescent composite nanoparticles via electrostatic assembly as a pH ratiometer

Abstract

Sandwich-like colloidal silica/CdTe quantum dots/silica nanoparticles are fabricated by efficient electrostatic assembly. They show remarkable stabilities and bright fluorescence, affording the application of pH ratiometric nanosensor.

PEGylation of protein-imprinted nanocomposites sandwiching CdTe quantum dots with enhanced fluorescence sensing selectivity

“…The amine-functionalized SiO 2 nanoparticles (denoted as SiO 2 –NH 2 ) were synthesized by a modified Stöber method. 42 Ammonium hydroxide (30 mL) and ethanol (500 mL) were mixed to a three-necked flask and at 40 °C for 20 min with mechanical stirring, then TEOS (5 mL) was added and the mixture was stirred overnight. APTES (0.5 mL) was added into the flask drop by drop and the reaction was continued for 24 h. The resultant SiO 2 –NH 2 particles were collected by centrifugation, and then washed with ethanol and water several times.…”

Photoluminescent Nanoparticles for Chemical and Biological Analysis and Imaging

“…Two examples of such supra-NP assemblies are shown in Figure . , These configurations can be achieved by covalent coupling, coordinate interactions, and electrostatic interactions. Examples include SiO 2 NP@QDs, ,− Au NP/SiO 2 @QDs, − Ag NP/SiO 2 @Au NCs, UCNP/SiO 2 @QDs, UCNP/SiO 2 @Au NPs, DDSNP@Au NPs, QD@Au NPs, QD-doped SiO 2 NP@CDs, IONP@Au NCs, IONP/SiO 2 @QDs, , IONP/SiO 2 @CQDs, and polymer NP@IONPs@QDs . It is commonplace, particularly with combinations of plasmonic NPs and LNPs, for there to be an intervening silica layer between the core and satellites. ,, In some cases, the assembled satellite NPs are also embedded in a silica shell around the core to render the assembly more robust. ,− , …”

“…555,560,563 In some cases, the assembled satellite NPs are also embedded in a silica shell around the core to render the assembly more robust. 554,[556][557][558]568 While not strictly an assembly of NPs, a final group of morphologies worth noting are those based on the synthesis of one NP on another, where one of these materials is photoluminescent. One possible morphology is a heterodimer (e.g., QD-FePt NPs, 573 IONP-Ag NCs 574 ), whereas another morphology synthesizes a shell of a nominal NP material around another NP (e.g., IONP/SiO 2 /UCNP-like shell, 575 IONP/QD-like shell, 576 QD/IONP-like shell, 577 Au NP/ DDSNP-like shell, 530 DDSNP/Au NP shell, 530 Au NP/ DDSNP-like shell/Au NP shell 530 ).…”

Pd nanocatalysts adsorbed onto silica nanoparticle coated indium tin oxide: a reusable nanozyme for glucose detection

“…The preparation of silica NPs (SiO 2 NPs) was achieved using a Sto ¨ber method. 23 Briefly, 15 mL NH 4 OH was added into 250 mL EtOH and the mixture was heated at 40 1C with stirring at 200 rpm for 30 min. TEOS (2.5 mL) was added and the mixture was left to react for 12 hours with constant stirring at 40 1C.…”