Multiplexed Analysis of Hg2+ and Ag+ Ions by Nucleic Acid-Functionalized CdSe/ZnS Quantum Dots and Their Use for Logic Gate Operations

Multiplexed Analysis of Hg²⁺ and Ag⁺ Ions by Nucleic Acid-Functionalized CdSe/ZnS Quantum Dots and Their Use for Logic Gate Operations

R. Freeman, T. Finder and I. Willner

Angew. Chem. Int. Ed., 48, 7818-7821 (2009).

A logical analysis: Nucleic acid functionalized CdSe/ZnS quantum dots are used for the optically selective multiplexed analysis of Hg²⁺ and Ag⁺ and the activation of logic gates in the presence of Ag⁺ and Hg²⁺, and for the activation of logic gates, by using the ions as inputs.

Logic Gates and Antisense DNA Devices Operating on a Translator Nucleic Acid Scaffold

Logic Gates and Antisense DNA Devices Operating on a Translator Nucleic Acid Scaffold

B. Shlyahovsky, Y. Li, O. Lioubashevski, J. Elbaz and I. Willner

ACS Nano. 3, 1831-1843 (2009).

Sensing of UO22+ and Design of Logic Gates by the Application of Supramolecular Constructs of Ion-Dependent DNAzymes

ensing of UO₂²⁺ and Design of Logic Gates by the Application of Supramolecular Constructs of Ion-Dependent DNAzymes

M. Moshe, J. Elbaz, and I. Willner

Nano Lett., 9, 1196-1200 (2009).

Supramolecular constructs composed of ion-dependent DNAzymes and their substrates were used to develop DNAzyme cascades that enabled the sensitive detection of UO2²⁺ or the activation of logic gate operations. The supramolecular complex between the UO2^2+-dependent DNAzyme and its substrate leads, in the presence of UO2²⁺, to the cleavage of the substrate and to the release of the HRP-mimicking DNAzyme that enables the optical analysis of UO2²⁺ (detection limit 1 nM). Similarly, supramolecular complexes between the Mg²⁺- and UO2²⁺-dependent DNAzymes and tailored substrates enables the design of the “OR” and “AND” logic gates, using Mg²⁺ and UO2²⁺ as inputs.

Coherent Activation of DNA Tweezers: A

oherent Activation of DNA Tweezers:  A "SET-RESET" Logic System

J. Elbaz, M. Moshe and I. Willner

Angew. Chem. Int. Ed., 48, 3834-3837 (2009).

Aptamer-substrate complexes activate the coherent operation of two tweezers that act as a "SET-RESET" logic system.

pH-Stimulated Concurrent Mechanical Activation of Two DNA

H-Stimulated Concurrent Mechanical Activation of Two DNA "Tweezers" – A "SET-RESET" Logic Gate System

J. Elbaz, Z.-G. Wang, R. Orbach and I. Willner

  Nano Lett., 2009, 9 (12), pp 4510–4514

Ligand and solvation effects on the Electronic Properties of Au55 clusters: a DFT study

Ligand and solvation effects on the Electronic Properties of Au₅₅ clusters: a DFT study

NANOLETTERS 2009 Vol. 9, No. 8 3007-3011

Ganga Periyasamy and F. Remacle

Reconfigurable Logic Devices on a Single Dopant Atom? Operation up to a Full Adder by Using Electrical Spectroscopy

Michael Klein, Gabriel P. Lansbergen, Jan A. Mol, Sven Rogge, Raphael D. Levine and Francoise Remacle

A silicon field-effect transistor is operated as a logic circuit by electrically addressing the ground and excited electronic states of an embedded single dopant atom. Experimental results—complemented by analytical and computational calculations—are presented. First, we show how a complete set of binary logic gates can be realized on the same hardware. Then, we show that these gates can be operated in parallel on the very same dopant up to the logic level of a full adder. To use the device not as a switch but as a full logic circuit, we make essential use of the excited electronic states of the dopant and of the ability to shift their energy by gating. The experimental ability to use two channels to measure the current flowing through the device and the conductance (dI/dV) allows for a robust reading of the output of the logic operations.

ChemPhysChem 2009, 10, 162 – 173

Copper rotaxane set-reset machine

Electrochemically Driven Sequential Machines: An Implementation of Copper Rotaxanes

Ganga Periyasamy, Jean-Paul Collin, Jean-Pierre Sauvage, Raphael D. Levine,  and Francoise Remacle

Chem. Eur. J.  15:  1310-1313, 2009.

We propose to use the redox states and ligand reorganization characteristics of a copper rotaxane mechanical machine[
2] to realize a finite-state machine, that is, a logic machine that possesses an integral memory unit.[3–7] These compounds
provide two definite advantages for the implementation of finite-state set–reset machines: 1) A large ligand reorganization
when the redox state of the Cu ion changes, which leads to a clear and reliably observable molecular hysteresis[8] and 2) a rate of reorganization comparable to the voltage sweep rate in cyclic voltammetry. We provide concrete experimental results and a simulation as proof of the principle of the operation of an all-electrochemical-cyclable finite-state machine.

Optically-Driven Atomic Coherences in a Pr:YSO Crystal

F. Beil, J. Klein, and T. Halfmann
Photonics and Nanostructures, in press
 
Abstract : We report on the experimental implementation of stimulated Raman adiabatic passage (STIRAP), electromagnetically induced transparency (EIT) and the retrieval of light pulses in a Pr.YSO crystal.
We apply coherent, adiabatic processes to control population dynamics and atomic coherences in selected hyperfine levels of the praseodymium dopants in the crystal. Our data demonstrate efficient adiabatic population transfer by conventional STIRAP as well as by an alternative transfer process, i.e. b-STIRAP. Moreover, we investigate dark resonances, driven by EIT in a L-type and in a V-type level scheme.We apply EIT to create atomic coherences in Pr:YSO. The persistent coherence is monitored by delayed retrieval of light pulses from the medium.

Figure Caption : Light pulses, retrieved from Pr:YSO after optical preparation by EIT (for different time delays of the retrieval with regard to the storage ­ indicated by different colours of the retrieved pulse)