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Abstract: Efficient ways are presented to accomplish photonic controlled‐phase‐flip gate and entangler with the assistance of imperfect double‐sided quantum‐dot‐microcavity systems, but without ancillary qubits. Compact quantum circuits for implementing entanglement swapping between photon pairs and electron pairs are then designed. Unity fidelities of the schemes can be achieved, and physical imperfections in the construction processes are detected by single‐photon detectors. Also, the efficiencies of the schemes can be further improved by repeating the operation processes when the undesired performances are detected. The evaluations show that the schemes are possible with current experiment parameters. [ABSTRACT FROM AUTHOR]

The antibiotic amoxicillin (AMX) was detected sensitively by a novel fluorescence probes composed with boron-doped carbon quantum dots (B-CQDs). B-CQDs with a 5:1 molar ratio of C atom versus B atom can be synthesized first by mixing citric acid with boric acid as a B source on suitable hydropyrolysis condition. The AMX in an aqueous solution was detected via fluorometry. Results showed that the as-prepared B-CQDs had nattier blue fluorescence, a narrow diameter range, a mean particle size of 2.3 nm, a multigraphite phase structure, and a quantum yield of 30.85%. The B-CQDs as probes can sensitively detect AMX in aqueous solution, and the fluorescence signal of the B-CQDs-AMX system was strengthened linearly with the increase in AMX concentration when in the antibiotic concentration range of 1.43–429.12 μmol·L−1 with limit of detection of 0.825 μmol·L−1. B-CQDs detected AMX mechanism as follows: the probes can be combined with antibiotic via primary hydrogen bond between them, and their combining abilities were enhanced by increasing the temperature of this sensing system in the range of 288–313 K. Unlabelled Image • Boric acid were introduced to prepare boron doped CQDs. • The fluorescence property and quantum yield of B-CQDs were more preferable than CQDs. • AMX in aqueous solutions were detected by B-CQDs based on the fluorescence enhancement. • The mechanism of AMX detected by B-CQDs was discussed in detail. [ABSTRACT FROM AUTHOR]

• Biomass waste was used to prepare high performance carbon quantum dots. • The prepared biomass carbon quantum dots exhibit sensitivity to Fe3+ ions and pH. • The biomass CQDs realized the quantitative detection of Fe3+ ions in pond water. In this work, some common and inexpensive biomass waste were used as carbon sources including orange peel, ginkgo biloba leaves, paulownia leaves and magnolia flower to prepare biomass carbon quantum dots (CQDs) by using a facile hydrothermal process. These biomass CQDs exhibited the advantages of homogeneous particle size, superior water solubility and stability, similar optical properties and surface functional group. The fluorescence quenching effect was observed when Fe3+ ions were added into CQDs solution. The experiment results showed that the as-prepared CQDs have a sensitive response to Fe3+ ions in the concentration range of 0.2−100 μM, and the limit of detection (LOD) could as low as 0.073 μM. More importantly, practical applications for the detection Fe3+ ions in pond water acquired satisfactory recoveries (94 %–108 %). Therefore, this work not only provided a new way for reusages of biomass waste, but also provided a novel alternative sensor for Fe3+ ions detection in real-world. [ABSTRACT FROM AUTHOR]

• A novel N-CQDs were prepared by facile solid-heat method using glycine and urea. • The N-CQDs possessed a relatively high fluorescence QY (21.04 %). • The N-CQDs exhibited very high sensitivity and selectivity to dopamine. • This sensor successfully used for dopamine detection in human serum and rat serum. Herein, a novel nitrogen-doped carbon quantum dots (N-CQDs) with bright blue fluorescence were prepared using glycine and urea by a facile solid-heat method. The prepared N-CQDs had a relatively high quantum yield (QY = 21.04 %), excellent photobleaching resistance, acid and alkali resistance. Moreover, it was used as fluorescent probe for the detection of dopamine (DA) with high selectivity and a low limit of detection (LOD = 0.0972 μM). Additionally, this fluorescent probe was successfully used to the determination of DA in human serum and rat serum with satisfactory recoveries (98.24 %–107.86 %), indicating this probe is was a promising biomolecular sensor for quantitation of DA in serum. [ABSTRACT FROM AUTHOR]

Herein, a water soluble AgInS 2 quantum dots (AIS QDs) with high sensitive and selective for dopamine (DA) were prepared through a clean and facile reflux method with the mercapto propionic acid (MPA) and polyethyleneimine (PEI) used as the co-modifiers. The fluorescence quench of as-fabricated AIS QDs displayed an excellent selectivity and sensitivity to the DA and they showed a good linear relationship with the low detection limit (2.84 nm) in the range of 0.5–300 μmol/L. The mechanism of fluorescence quench may attributed to the photoinduced electrons migrated from AIS QDs to dopamine quinone, which originated from the oxidization of DA by ambient O 2. Our work shows a promising prospect of designing and preparing AIS QDs used as the fluorescence sensors for DA detection. Image 1 • Water soluble AIS QDs were prepared via a facile hydrothermal method. • MPA and PEI used as the co-modifiers to synthesize the AIS QDs. • AIS QDs displayed high sensitive and selective for dopamine (DA). • The detect limit of DA as low as 2.84 nM based on AIS QDs fluorescence probe. [ABSTRACT FROM AUTHOR]