Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.
At a glance
- Fantastic voyage: designing self-powered nanorobots. Angew. Chem. Int. Ed. 51, 8434–8445 (2012). , &
- Intelligent, self-powered, drug delivery systems. Nanoscale 5, 1273–1283 (2013). et al.
- Can man-made nanomachines compete with nature biomotors? ACS Nano 3, 4–9 (2009).
- Nanorobots: the ultimate wireless self-propelled sensing and actuating devices. Chem. Asian J. 4, 1402–1410 (2009). &
- Biomimetic behavior of synthetic particles: from microscopic randomness to macroscopic control. Phys. Chem. Chem. Phys. 12, 1423–1425 (2010). , , &
- Rolled-up nanotech on polymers: from basic perception to self-propelled catalytic microengines. Chem. Soc. Rev. 40, 2109–2119 (2011). , , &
- Nanolocomotion—catalytic nanomotors and nanorotors. Small 6, 159–167 (2010). , , &
- Motility of catalytic nanoparticles through self-generated forces. Chem Eur. J. 11, 6462–6470 (2005). , &
- Nanomaterials meet microfluidics. Chem. Commun. 47, 5671–5680 (2011).
- Powering nanorobots. Sci. Am. 300, 72–77 (2009). &
- A review of micropumps. J. Micromech. Microeng. 14, R35–R64 (2004). &
- MEMS-based micropumps in drug delivery and biomedical applications. Sens. Actuat. B Chem. 130, 917–942 (2008). , , &
- Therapeutic applications of implantable drug delivery systems. J. Pharmacol. Toxicol. Methods 40, 1–12 (1998). &
- Miniaturized total analysis systems for biological analysis. Fresenius J. Anal. Chem. 366, 525–539 (2000). , &
- A silicon integrated miniature chemical analysis system. Sens. Actuat. B Chem. 6, 57–60 (1992). , , &
- Integrated system for rapid PCR-based DNA analysis in microfluidic devices. Anal. Chem. 72, 2995–3000 (2000). et al.
- Functional integration of PCR amplification and capillary electrophoresis in a microfabricated DNA analysis device. Anal. Chem. 68, 4081–4086 (1996). et al.
- Self-powered microscale pumps based on analyte-initiated depolymerization reactions. Angew. Chem. Int. Ed. 51, 2400–2404 (2012). et al.
- Catalytic micropumps: microscopic convective fluid flow and pattern formation. J. Am. Chem. Soc. 127, 17150–17151 (2005). et al.
- Hydrazine fuels for bimetallic catalytic microfluidic pumping. J. Am. Chem. Soc. 129, 7762–7763 (2007). , , , &
- A biomimetic, self-pumping membrane. Adv. Mater. 22, 4823–4825 (2010). &
- Light-driven titanium-dioxide-based reversible microfireworks and micromotor/micropump systems. Adv. Funct. Mater. 20, 1568–1576 (2010). , , &
- Catalytically induced electrokinetics for motors and micropumps. J. Am. Chem. Soc. 128, 14881–14888 (2006). et al.
- Tunable catalytic tubular micro-pumps operating at low concentrations of hydrogen peroxide. Phys. Chem. Chem. Phys. 13, 10131–10135 (2011). , , &
- Measurements and modeling of two-phase flow in microchannels with nearly constant heat flux boundary conditions. J. Microelectromech. Syst. 11, 12–19 (2002). et al.
- Chemical power for microscopic robots in capillaries. Nanomedicine: Nanotech. Biol. Med. 6, 298–317 (2010). &
- Triggered ‘on/off’ micropumps and colloidal photodiode. J. Am. Chem. Soc. 134, 15688–15691 (2012). , , &
- A valve-less diffuser micropump for microfluidic analytical systems. Sens. Actuat. B Chem. 72, 259–265 (2001). , , , &
- Enzyme molecules as nanomotors. J. Am. Chem. Soc. 135, 1406–1414 (2013). et al.
- Substrate catalysis enhances single-enzyme diffusion. J. Am. Chem. Soc. 132, 2110–2111 (2010). , , , &
- Molecular propulsion: chemical sensing and chemotaxis of DNA driven by RNA polymerase. J. Am. Chem. Soc. 131, 5722–5723 (2009). , , , &
- Glucose-responsive microgels integrated with enzyme nanocapsules for closed-loop insulin delivery. ACS Nano 7, 8, 6758–6766 (2013). et al.
- Enzyme-amplified array sensing of proteins in solution and in biofluids. J. Am. Chem. Soc. 132, 5285–5289 (2010). et al.
- Predominant role of catalase in the disposal of hydrogen peroxide within human erythrocytes. Blood 87, 1595–1599 (1996). et al.
- Lipase protein engineering. Biochim. Biophys. Acta 1543, 223–228 (2000).
- Glucose oxidase as an analytical reagent. Crit. Rev. Anal. Chem. 25, 1–42 (1995). &
- Designing phoretic micro- and nano-swimmers. New J. Phys. 9, 126 (2007). , &
- Propulsion of a molecular machine by asymmetric distribution of reaction products. Phys. Rev. Lett. 94, 220801 (2005). , &
- Diffusiophoresis: migration of colloidal particles in gradients of solute concentration. Separ. Purif. Method 13, 67–103 (1984). &
- A polymerization-powered motor. Angew. Chem. Int. Ed. 50, 9374–9377 (2011). , , , &
- Electrokinetic locomotion by reaction induced charge auto-electrophoresis. J. Fluid Mech. 680, 31–66 (2011). &
- Self-motile colloidal particles: from directed propulsion to random walk. Phys. Rev. Lett. 99, 048102 (2007). et al.
- Osmotic propulsion: the osmotic motor. Phys. Rev. Lett. 100, 158303 (2008). &
- Motion analysis of self-propelled Pt−silica particles in hydrogen peroxide solutions. J. Phys. Chem. A 114, 5462–5467 (2010). , , &
- Colloid transport by interfacial forces. Ann. Rev. Fluid Mech. 21, 61–99 (1989).
- Motion of a particle generated by chemical gradients. Part 1. Non-electrolytes. J. Fluid Mech. 117, 107–121 (1982). , &
- Motion of a particle generated by chemical gradients. Part 2. Electrolytes. J. Fluid Mech. 148, 247–269 (1984). , , &
- On convection currents in a horizontal layer of fluid, when the higher temperature is on the underside. Phil. Mag. 32, 529–546 (1916).
- Macroscopic self-propelled objects. Chem. Asian J. 7, 1994–2002 (2012). &
- Receptor binding of biosynthetic human insulin on isolated pig hepatocytes. Diabetes Care 4, 2, 235–237 (1981).
- Supplementary information (5,443 KB)
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