Effective Synthesis of Patterned Polymer Brushes with Tailored Multiple Graft Densities

This paper reports an effective method to prepare patterned polymer brushes on surfaces with tailored graft densities. High-density (concentrated), moderate-density (semidiluted), and low-density (diluted) polymer brushes were fabricated in patterned manners, offering defined three-dimensional patterned structures. This method uses a middle/near-UV (≥250 nm) lamp and needs only a short time (≤10 min) to fabricate prepatterns of the initiator, in sharp contrast to the previous high-energy lithography and time-consuming processes. The obtained patterned brush served as a molecular (protein) repellent/adsorptive interface based on a graft-density-dependent size-exclusion effect. This method is facile and accessible to wide ranges of tunable density and pattern shapes, which are attractive for extensive use.

Designed synthesis of aptamer-immobilized magnetic mesoporous silica/Au nanocomposites for highly selective enrichment and detection of insulin

We designed and synthesized aptamer-immobilized magnetic mesoporous silica/Au nanocomposites (MMANs) for highly selective detection of unlabeled insulin in complex biological media using MALDI-TOF MS. The aptamer was easily anchored onto the gold nanoparticles in the mesochannels of MMANs with high capacity for highly efficient and specific enrichment of insulin. With the benefit from the size-exclusion effect of the mesoporous silica shell with a narrow pore size distribution (∼2.9 nm), insulin could be selectively detected despite interference from seven untargeted proteins with different size dimensions. This method exhibited an excellent response for insulin in the range 2-1000 ng mL(-1). Moreover, good recoveries in the detection of insulin in 20-fold diluted human serum were achieved. We anticipate that this novel method could be extended to other biomarkers of interest and potentially applied in disease diagnostics.