Bio-inspired porous antenna-like nanocube/nanowire heterostructure as ultra-sensitive cellular interfaces

Abstract

In this study, an unconventional antenna-like heterostructure comprised of arrays of nanoporous Prussian blue (PB) nanocube heads/TiO 2 nanowire (NW) arms (PB-TiO 2 ) is developed for efficient three-dimensional interfacial sensing of small molecules and cellular activities. Inspired by insect tentacles, which are comprised of both target recognition and signal transduction units, one-dimensional TiO 2 NW arrays are grown, followed by selective growth of nanoporous PB nanocubes on the tips of the NW arrays. Due to their high selectivity and bioaffinity toward cells, long biostability under a cell culture adhesion condition (up to 108 h) is obtained, and with its inherent bio-mimetic enzymatic activity, the obtained nanoporous PB nanocubes (head segment) serve as robust substrates for site-selective cell adhesion and culture, which allows for sensitive detection of H 2 O 2 . Simultaneously, the single-crystalline TiO 2 NWs (arm segment) provide efficient charge transport for electrode substrates. Compared with PB-functionalized planar electrochemical interfaces, the PB-TiO 2 antenna NW biointerfaces exhibit a substantial enhancement in electrocatalytic activity and sensitivity for H 2 O 2 , which includes a low detection limit (B20 nM), broad detection range (10 À8 to 10 À5 M), short response time (B5 s) and long-term biocatalytic activity (up to 6 months). The direct cultivation of HeLa cells is demonstrated on the PB-TiO 2 antenna NW arrays, which are capable of sensitive electrochemical recording of cellular activity in real time, where the results suggest the uniqueness of the biomimic PB-TiO 2 antenna NWs for efficient cellular interfacing and molecular recognition.

Self-curled coral-like γ-Al 2 O 3 nanoplates for use as an adsorbent

“…Enlarged TEM image on a single nanoplate shows that uniform pores with size of $2.5 nm appeared on the nanoplates (inset of [24], indicating monolayer adsorption at low pressure due to existence of micropores and multilayer adsorption at higher pressure. The hysteresis loops caused by capillary condensation indicate the existence of mesopores [25,26]. Further, the typical H3 type hysteresis loops show that the mesopores are slit-like pores formed by aggregation of plate-like particles [24].…”

New faces of porous Prussian blue: interfacial assembly of integrated hetero-structures for sensing applications

“…Recently, Kurihara et al have developed a direct printing method via hybrid surface modification for transforming insoluble PB into dispersible nanoparticles in water and various hydrophilic and hydrophobic organic solvents. 177 The low-potential monitoring of hydrogen peroxide provides both high sensitivity and high selectivity in the presence of easily oxidizable compounds. 15a-d).…”

“…25 Porous Prussian blue nanostructures, one of the most efficient electrochemical mediators, have been used as an enzyme-based biosensor for biomedicine and environmental analyses. 3,16 In previous studies, they have been demonstrated to be applicable to the sensing of hydrogen peroxide at a low applied potential, allowing the integration of oxidase enzymes while reducing other electrochemical interferents. 3,16 In previous studies, they have been demonstrated to be applicable to the sensing of hydrogen peroxide at a low applied potential, allowing the integration of oxidase enzymes while reducing other electrochemical interferents.…”

Interfacial assembly of mesoporous nanopyramids as ultrasensitive cellular interfaces featuring efficient direct electrochemistry

“…46,52 It has been reported that phorbol 12-myristate-13-acetate (PMA) can trigger H 2 O 2 generation by living cells. 14,53 For the electrode without AuNPs, the H 2 O 2 oxidation current is insignificant when a low concentration of PMA (5 μg ml − 1 ) is added to the surface of cardiomyocytes (Figure 3f, curve i). In contrast, the electrode with AuNPs shows a large H 2 O 2 reduction current (Figure 3f, curve ii).…”

“…No response is observed in the control experiments for NPI-Au-Cyt c without cells but with the same PMA injection or for NPI-Au-Cyt c with cultured cells but without PMA dimethyl sulfoxide injection. In addition, after injection of catalase (a selective scavenger of H 2 O 2 ), 53,35 the cathodic current caused by PMA injection for the NPI-Au-Cyt c electrode with cultured cells almost decreases to the original level before PMA injection (Figure 3f, curve ii). Accordingly, the cathodic current is ascribed to PMA-induced H 2 O 2 released from cultured cells with a detection limit of~0.2 nm for H 2 O 2 , which is electrocatalyzed on the 3D NPI interface.…”