Highly sensitive and selective chemosensors for Cu2+and Al3+based on photoinduced electron transfer (PET) mechanism

RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27282-27289 ◽  
Author(s):  
Santosh Chemate ◽  
Nagaiyan Sekar

Two new fluorescent PET chemosensors were synthesised from an acridine core. The sensors can be used to monitor Cu2+and Al3+in CH3CN. The detection limits for7a–Cu2+and7b–Al3+were calculated to be 2.8 × 10−7M and 5.8 × 10−7M, respectively.

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 65 ◽  
Author(s):  
Han Zhao ◽  
Xinying Xiang ◽  
Mingjian Chen ◽  
Changbei Ma

This study describes a novel quencher-free fluorescent method for ochratoxin A (OTA) detection based on the photoinduced electron transfer (PIET) between guanine and fluorophore. In the absence of OTA, carboxyfluorescein (FAM)-labeled aptamer can partly hybridize with the complementary strand of OTA aptamer (OTA-cAPT), which contains four guanines at its 3′-end. As a result, the fluorescence of FAM is quenched due to PIET and stacked guanines. In the presence of OTA, FAM-labeled OTA aptamer can bind specifically to OTA, and thereby the high fluorescence intensity of the dye can be maintained. Under the optimal conditions, the method had a detection limit of 1.3 nM. In addition, the method we proposed is highly sensitive and specific for OTA. Furthermore, the method was proven to be reliable based on its successful application in the detection of OTA in red wine samples. Therefore, this promising, facile, and quencher-free method may be applied to detect other toxins by using other appropriate aptamers.


2020 ◽  
Author(s):  
Rishikesh Kulkarni ◽  
Anneliese Gest ◽  
Chun Kei Lam ◽  
Benjamin Raliski ◽  
Feroz James ◽  
...  

<p>High signal-to-noise optical voltage indicators will enable simultaneous interrogation of membrane potential in large ensembles of neurons. However, design principles for voltage sensors with high sensitivity and brightness remain elusive, limiting the applicability of voltage imaging. In this paper, we use molecular dynamics (MD) simulations and density functional theory (DFT) calculations to guide the design of a bright and sensitive green-fluorescent voltage-sensitive fluorophore, or VoltageFluor (VF dye), that uses photoinduced electron transfer (PeT) as a voltage-sensing mechanism. MD simulations predict an 11% increase in sensitivity due to membrane orientation, while DFT calculations predict an increase in fluorescence quantum yield, but a decrease in sensitivity due to a decrease in rate of PeT. We confirm these predictions by synthesizing a new VF dye and demonstrating that it displays the expected improvements by doubling the brightness and retaining similar sensitivity to prior VF dyes. Combining theoretical predictions and experimental validation has resulted in the synthesis of the highest signal-to-noise green VF dye to date. We use this new voltage indicator to monitor the electrophysiological maturation of human embryonic stem cell-derived medium spiny neurons. </p>


Author(s):  
Anton J Stasyuk ◽  
Olga A. Stasyuk ◽  
Miquel Solà ◽  
Alexander Voityuk

Suitanes, a new class of two-component mechanically interlocked systems, have recently been developed. In this work, we report a detailed study of photoinduced electron transfer processes in the suit[3]anes consisting...


2021 ◽  
Vol 154 (5) ◽  
pp. 054104
Author(s):  
D. Wellnitz ◽  
G. Pupillo ◽  
J. Schachenmayer

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