Highly Sensitive and Reliable NIR Luminescent Sensing Toward Nitro‐Aromatic Antibiotics in Water

Abstract

Near‐infrared (NIR) light features less photon scatter and deeper penetration, thereby providing a sensitive and reliable platform for qualifying and quantifying trace organic contaminants in water medium. Herein, a lanthanide/β‐diketone complex, Yb(dmh)3(phen) (dmh = 2,6‐dimethyl‐3,5‐heptanedione, phen = 1,10‐phenanthroline), is synthesized and performs characteristic NIR luminescence of Yb3+ ions. The outstanding photophysical properties result from the combination effects of excited‐state inter‐ligand charge transfer, ligand‐to‐metal energy transfer, and high structural symmetry. Noteworthily, this NIR luminophore exhibits state‐of‐the‐art sensitivity toward nitro‐aromatic antibiotics in water. The limits of detection are lower to sub‐nanomolar level for nitroimidazoles (metronidazole 0.18 nM; dimetridazole 0.23 nM; ornidazole 0.28 nM) and even picomolar level for nitrofurans (nitrofurantoin 43 pM; nitrofurazone 46 pM). This exciting sensitivity attributes to photo‐induced electron transfer and inner filter effect between sensor and adsorbed analytes. The sensor is also capable of distinguished stability, selectivity, competitiveness, and anti‐interference, which makes it far better suited to the commercial application. The successfully developed technique of NIR luminescence sensing extends the platform of optical devices and sensing materials, being of practical value in monitoring water quality.

Ligand as Buffer for Improving Chemical Stability of Coordination Polymers

“…32 Based on the multiemissive nature of the Eu/Na−D-DBTA sensor, we designed a multi-SV equation by simultaneously considering the fluorescence intensification at 440 nm and luminescence quenching at 614 nm according to the equation RI = (I 440 / I 0 440 )/(I 614 /I 0 614 ) − 1, where RI is the relative intensity and I 440 , I 614 , I 0 440 , and I 0 614 are the luminescence intensities at 440 and 614 nm after and before addition of L-Trp analyte, respectively. 33 Based on this multi-SV equation, we obtained an obviously improved sensitivity (K SV = 1.57 × 10 5 M −1 , LOD = 19 nM) compared with the classic SV equation with exclusive monitoring at 440 or 614 nm (where RI = I 0 /I) (Figure S13). Meanwhile, the R 2 value increased to >0.999, which represented the ultrahigh reliability of the Eu/Na−D-DBTA sensor toward the L-Trp analyte.…”

“…The classical Stern–Volmer (SV) equation, RI = I 0 / I = 1 + K SV [C], was used to determine the limits of detection (LODs) as 316 nM for monitoring at 440 nm and 2.36 μM for monitoring at 614 nm (Figure S13). Based on the multiemissive nature of the Eu/Na– d -DBTA sensor, we designed a multi-SV equation by simultaneously considering the fluorescence intensification at 440 nm and luminescence quenching at 614 nm according to the equation RI = ( I 440 / I 0 440 )/( I 614 / I 0 614 ) – 1, where RI is the relative intensity and I 440 , I 614 , I 0 440 , and I 0 614 are the luminescence intensities at 440 and 614 nm after and before addition of l -Trp analyte, respectively . Based on this multi-SV equation, we obtained an obviously improved sensitivity ( K SV = 1.57 × 10 5 M –1 , LOD = 19 nM) compared with the classic SV equation with exclusive monitoring at 440 or 614 nm (where RI = I 0 / I ) (Figure S13).…”

“…An LOD of 191 nM was obtained using the multi-SV equation (Figure S21). The outstanding selectivity and recyclability indicated that l -Trp@Eu/Na– d -DBTA was a potential candidate for detecting aqueous l -Lys (Figures S22–S25). Furthermore, the l -Trp@Eu/Na– d -DBTA sensor exhibited stable sensitivity toward l -Lys in acid/alkaline aqueous solutions over the pH range from 3 to 11 (Figures b, S26, and S27).…”

Crafting Near‐Infrared Photonics via the Programmable Assembly of Organic Heterostructures at Multiscale Level

“…Organic materials with NIR emission have been widely used in optical communication, [1][2][3] bio-imaging, [4][5][6] smart sensing, [7][8][9] and night vision devices [10,11] because of their low optical loss, high penetration and free light pollution. Up to today, numerous techniques have been adopted to realize the NIR emission, such as designing and synthesizing new molecules, [12][13][14][15] and doping DOI: 10.1002/adfm.202312478 metal/rare earth elements.…”

Distinguishing nitroimidazoles from nitrofurans via luminescence sensing

“…7 In recent years, our group has pioneered the synthesis of a plethora of luminescent sensors, tailored for antibiotic detection in aqueous and biological matrices. 8 Despite the advances, discerning NMs from NFs using luminescence spectroscopy remains challenging due to their similar nitro-heterocyclic structures, leading to indistinguishable photophysical responses.…”