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Journal of Nanomaterials
Volume 2017, Article ID 1610597, 10 pages
Research Article

Structural and Chemical Characterization of Silica Spheres before and after Modification by Silanization for Trypsin Immobilization

1Embrapa Recursos Genéticos e Biotecnologia, Laboratório de Espectrometria de Massa e Laboratório de Nanobiotecnologia, Parque Estação Biológica Final W5 Norte, 70770-917 Brasília, DF, Brazil
2Universidade de Brasília, Instituto de Ciências Biológicas, Campus Universitário Darcy Ribeiro, 79910-900 Brasília, DF, Brazil
3Universidade Federal do Oeste da Bahia, Centro das Ciências Biológicas e da Saúde, Campus Edgar Santos, 47808-021 Barreiras, BA, Brazil

Correspondence should be addressed to Eduardo F. Barbosa; moc.liamg@sednanrefodraudeasobrab and Luciano P. Silva; rb.aparbme@oniluap.onaicul

Received 19 March 2017; Revised 2 June 2017; Accepted 13 June 2017; Published 13 July 2017

Academic Editor: P. Davide Cozzoli

Copyright © 2017 Eduardo F. Barbosa and Luciano P. Silva. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In the last decades, silica particles of a variety of sizes and shapes have been characterized and chemically modified for several applications, from chromatographic separation to dental supplies. The present study proposes the use of aminopropyl triethoxysilane (APTS) silanized silica particles to immobilize the proteolytic enzyme trypsin for the development of a bioreactor. The major advantage of the process is that it enables the polypeptides hydrolysis interruption simply by removing the silica particles from the reaction bottle. Silanized silica surfaces showed significant morphological changes at micro- and nanoscale level. Chemical characterization showed changes in elemental composition, chemical environment, and thermal degradation. Their application as supports for trypsin immobilization showed high immobilization efficiency at reduced immobilization times, combined with more acidic conditions. Indirect immobilization quantification by reversed-phase ultrafast high performance liquid chromatography proved to be a suitable approach due to its high linearity and sensitivity. Immobilized trypsin activities on nonmodified and silanized silica showed promising features (e.g., selective hydrolysis) for applications in proteins/peptides primary structure elucidation for proteomics. Silanized silica system produced some preferential targeting peptides, probably due to the hydrophobicity of the nanoenvironment conditioned by silanization.