. Author manuscript; available in PMC: 2019 Jul 1.

Published in final edited form as: J Colloid Interface Sci. 2018 Feb 20;521:261–279. doi: 10.1016/j.jcis.2018.02.053

Table 2.

The most frequently used silanes used for surface modification on silica nanoparticles (NPs) and their functions.

Silanes	Function Group	Application
(3-aminopropyl)trimethoxysil ane (APTMS) (3-aminopropyl)triethoxysilan e (APTES)	−NH₂	Reduced aggregation¹⁰⁵, Fluorescent labeling¹⁴⁴, Surface charge modification¹⁴⁵, DNA binding and protection from enzymatic cleavage¹⁴⁹
(3-mercaptopropyl)-trimethox ysilane (MPTMS)	−SH	Conjugate with maleimides¹⁰⁶, Thiol/disulfide exchange reactions to attach oligonucleotides¹⁵⁰, Surface charge modification^{32, 151}
Polyethylene glycol-silane (PEG-silane)	−PEG	Increased circulation time¹⁵², Reduced aggregation and increase particle dispersity in aqueous solution¹²⁷
Alkylsilane	Alkyl chain	Hydrophobic coating¹⁵³, Increase ultrasound contrast¹⁵⁴
Carboxyethylsilanetriol	−COOH	Functionalize silica NPs and provide reactive sites for amine¹⁵⁵
3-trihydroxysilylpropyl methylphosphonate	−PO₃−	Functionalize silica NPs and provide reactive sites for amine¹⁵⁶
(3-isocyanatopropyl)-triethox ysilane	−NCO	Functionalize silica NPs and provide reactive sites for amine¹⁵⁷