Related Experiment Video
Updated: May 30, 2026

Synthesis of Wavelength-shifting DNA Hybridization Probes by Using Photostable Cyanine Dyes
Published on: July 6, 2016
Synthesis and spectroscopic characterization of red-shifted spironaphthoxazine based optical switch probes
Chutima Petchprayoon1, Gerard Marriott
1Department of Bioengineering, University of California, Berkeley, CA 94720, USA.
Abstract:
Spironaphthoxazine (NISO) is an efficient optical switch probe that has applications in high contrast detection of Foerster resonance energy transfer (FRET) using optical lock-in detection (OLID). NISO exists in two distinct states spiro (SP) and merocyanine (MC) that can be independently controlled by using alternate irradiation with near ultraviolet and visible light. Unfortunately, the SP-state of NISO has an absorption centered at 350 nm, which may lead to phototoxic effects when manipulating the probe within a living cell. To overcome this problem we introduce new, red-shifted amino substituted NISO probes compared to NISO that undergo an efficient SP to MC transition in response to irradiation by using 405-nm light, which is less damaging to living cells. This study details the synthesis of amino-substituted NISO and their N-hydroxysuccinimide ester and maleimide derivatives and their use in generating covalent attached protein conjugates. This study also presents a characterization of the spectroscopic and optical switching properties of these red-shifted NISO probe in solution.
Related Concept Videos
UV–Vis Spectroscopy: Molecular Electronic Transitions
NMR Spectroscopy: Chemical Shift Overview
For instance, the proton...
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in the...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds

