Qian Luo,Nan Ding,Hongxiu Chen,Yaqin Zhang,Miao Zhang,Wenli Gao,Yuanhua Li,Kejun Feng,Xingbo Shi
Effective identification of sulfur ions (S 2- ) in foodstuff is crucial for food safety and human health, but it remains challenging. Traditional single-mode colorimetric sensing methods are simple and sensitive, but are prone to interference from colored substances which can lead to false positives or negatives results. Herein, we develop a novel “mix-response” biosensor for colorimetric and photothermal dual-mode detection of S 2- with good simplicity, sensitivity and portability. In this biosensor, silver-doping Prussian blue nanoparticle (SPB NPs) was used as signal output component, which not only exhibits blue color characteristics, but also has photothermal conversion properties activated by near-infrared (NIR) laser. Upon increasing the S 2- concentration, the prepared SPB NPs undergo etching, leading to the formation of new silver sulfide precipitation (Ag 2 S), along with different colorimetric and photothermal response signals. For the portable visualization of S 2- , the color information was recorded by a smartphone in combination with RGB (red channel) analysis and the evolution of the photothermal signal was documented by a thermal imager. The introduction of smartphone and handheld thermal imager in this “mix-response” biosensor makes it suitable for on-site quantitative detection of S 2- without sophisticated instrument. Moreover, the development of this “mix-response” biosensor does not need the use of recognition probes (e.g. aptamers and reaction intermediates), thereby simplifying the construct procedures of sensing strategies and improving the economic efficiency of detection. More importantly, the photothermal response signals can overcome the interference of colored substances in foods, thereby reducing the false positives or negatives of the detection results.
Zhe Hao,Xiaodong Lin,Jinjie Li,Yanliang Yin,Xia Gao,Shuo Wang,Yaqing Liu
Bacterial infection is a growing public health concern and causes a huge medical and financial burden. It is of significance to efficiently construct multifunctional platforms for bacterial point-of-care testing (POCT) and elimination. Herein, near-infrared (NIR) light-responded vancomycin-doped prussian blue nanoparticles (PB-VAN NPs ) with high efficient photothermal conversion was synthesized for binding, dual-mode portable detection, and elimination of bacteria. The PB-VAN NPs can bind to the surface of Gram-positive bacteria such as Staphylococcus aureus ( S. aureus ), forming complex of PB-VAN NPs / S. aureus . After being centrifugated, the suspension solution of PB-VAN NPs can stimulate perfluorohexane (PFH) to rapidly release oxygen (O 2 ) under NIR irradiation. Thus, the bacteria can be sensitively detected with portable pressure meter as signal reader, reporting a limit of detection (LOD) of 1.0 CFU mL -1 . On the other side, the sediment of PB-VAN NPs / S. aureus can be detected via thermal camera, reporting a LOD of 1.0 CFU mL -1 . Interestingly, the bacteria can be effectively inactivated with the local temperature elevation during temperature-based detection. The antibacterial efficiency reaches as high as 99.8%. The developed multifunctional nanoplatform not only provides a straightforward “mix-then-test” way for portable detection of bacteria with high sensitivity, also realizes high efficiency elimination of bacteria simultaneously. The developed strategy was further applied for promoting wound healing of bacteria-infected mice.
危险品化学品经营许可证（带存储）