Imaging cellular membrane potential through ionization of quantum dots

Recent interest in quantum dots (QDs) stems from the plethora of potential applications that arises from their tunable absorption and emission profiles, high absorption cross sections, resistance to photobleaching, functionalizable surfaces, and physical robustness. The emergent use of QDs in biological imaging exploits these and other intrinsic properties. For example, quantum confined Stark effect (QCSE), which describes changes in the photoluminescence (PL) of QDs driven by the application of an electric field, provides an inherent means of detecting changes in electric fields by monitoring QD emission and thus points to a ready mean of imaging membrane potential (and action potentials) in electrically active cells. Here we examine the changing PL of various QDs subjected to electric fields comparable to those found across a cellular membrane. By pairing static and timeresolved PL measurements, we attempt to understand the mechanism driving electric-field-induced PL quenching and ultimately conclude that ionization plays a substantial role in initiating PL changes in systems where QCSE has traditionally been credited. Expanding on these findings, we explore the rapidity of response of the QD PL to applied electric fields and demonstrate changes amply able to capture the millisecond timescale of cellular action potentials.

[1]  Shimon Weiss,et al.  Single Molecule Quantum-Confined Stark Effect Measurements of Semiconductor Nanoparticles at Room Temperature , 2012, ACS nano.

[2]  Igor L. Medintz,et al.  Nanoparticle targeting to neurons in a rat hippocampal slice culture model , 2012, ASN neuro.

[3]  C. Galland,et al.  Two types of luminescence blinking revealed by spectroelectrochemistry of single quantum dots , 2011, Nature.

[4]  Clare E. Rowland,et al.  Electric Field Modulation of Semiconductor Quantum Dot Photoluminescence: Insights Into the Design of Robust Voltage-Sensitive Cellular Imaging Probes. , 2015, Nano letters.

[5]  A. Maccione,et al.  Large-scale, high-resolution electrophysiological imaging of field potentials in brain slices with microelectronic multielectrode arrays , 2012, Front. Neural Circuits.

[6]  Igor L. Medintz,et al.  Selecting improved peptidyl motifs for cytosolic delivery of disparate protein and nanoparticle materials. , 2013, ACS nano.

[7]  Jesse D. Marshall,et al.  Optical strategies for sensing neuronal voltage using quantum dots and other semiconductor nanocrystals. , 2013, ACS nano.

[8]  Igor L. Medintz,et al.  Förster resonance energy transfer investigations using quantum-dot fluorophores. , 2006, Chemphyschem : a European journal of chemical physics and physical chemistry.

[9]  M. Bawendi,et al.  Quantum-confined stark effect in single CdSe nanocrystallite quantum dots , 1997, Science.

[10]  Alina M. Schimpf,et al.  Size dependence of negative trion Auger recombination in photodoped CdSe nanocrystals. , 2014, Nano letters.

[11]  U. Kortshagen,et al.  Universal size-dependent trend in auger recombination in direct-gap and indirect-gap semiconductor nanocrystals. , 2009, Physical review letters.

[12]  Stefan R. Pulver,et al.  Ultra-sensitive fluorescent proteins for imaging neuronal activity , 2013, Nature.

[13]  Rafael Yuste,et al.  Imaging Voltage in Neurons , 2011, Neuron.

[14]  Uri Banin,et al.  Electric field induced switching of the fluorescence of single semiconductor quantum rods. , 2005, Nano letters.

[15]  Igor L. Medintz,et al.  Quantum dot-based resonance energy transfer and its growing application in biology. , 2009, Physical chemistry chemical physics : PCCP.

[16]  W. Webb,et al.  Water-Soluble Quantum Dots for Multiphoton Fluorescence Imaging in Vivo , 2003, Science.

[17]  Klimov,et al.  Quantization of multiparticle auger rates in semiconductor quantum dots , 2000, Science.

[18]  Stephen Ducharme,et al.  Electrical control of photoluminescence wavelength from semiconductor quantum dots in a ferroelectric polymer matrix , 2011 .

[19]  G. Salama,et al.  A naphthyl analog of the aminostyryl pyridinium class of potentiometric membrane dyes shows consistent sensitivity in a variety of tissue, cell, and model membrane preparations , 1992, The Journal of Membrane Biology.

[20]  V. Bulović,et al.  Bias-induced photoluminescence quenching of single colloidal quantum dots embedded in organic semiconductors. , 2007, Nano letters.

[21]  Yasuhiro Shirasaki,et al.  Study of field driven electroluminescence in colloidal quantum dot solids , 2012 .

[22]  Igor L. Medintz,et al.  Functionalizing nanoparticles with biological molecules: developing chemistries that facilitate nanotechnology. , 2013, Chemical reviews.

[23]  Christophe Danelon,et al.  Multifunctional lipid/quantum dot hybrid nanocontainers for controlled targeting of live cells. , 2006, Angewandte Chemie.

[24]  Moungi G. Bawendi,et al.  Photoconductivity in CdSe quantum dot solids , 2000 .

[25]  David A. B. Miller,et al.  Electroabsorption of highly confined systems: Theory of the quantum‐confined Franz–Keldysh effect in semiconductor quantum wires and dots , 1988 .

[26]  P. Barbara,et al.  Effect of electric field on the photoluminescence intensity of single CdSe nanocrystals , 2007 .

[27]  N. Thakor,et al.  Recent progress in voltage-sensitive dye imaging for neuroscience. , 2014, Journal of nanoscience and nanotechnology.

[28]  D. Ricard,et al.  Evidence of strong Auger recombination in semiconductor‐doped glasses , 1987 .

[29]  Philip E. Dawson,et al.  Delivery and tracking of quantum dot peptide bioconjugates in an intact developing avian brain. , 2015, ACS chemical neuroscience.

[30]  Igor L. Medintz,et al.  Quantum dot-based multiphoton fluorescent pipettes for targeted neuronal electrophysiology , 2014, Nature Methods.

[31]  V. Wood,et al.  Origins of Low Quantum Efficiencies in Quantum Dot LEDs , 2013 .

[32]  A. Green.  Psychopharmacology: The Fourth Generation of Progress , 1996 .

[33]  D. Engelman,et al.  Lipid bilayer thickness varies linearly with acyl chain length in fluid phosphatidylcholine vesicles. , 1983, Journal of molecular biology.

[34]  T. V. Shubina,et al.  Quantum-size stark effect in semiconductor microcrystals , 1990 .

[35]  Rafael Yuste,et al.  Nanotools for neuroscience and brain activity mapping. , 2013, ACS nano.

[36]  R. Nitschke,et al.  Quantum dots versus organic dyes as fluorescent labels , 2008, Nature Methods.

[37]  Igor L. Medintz,et al.  Two‐Photon Excitation of Quantum‐Dot‐Based Fluorescence Resonance Energy Transfer and Its Applications , 2007 .