Peng Shen,Yuqian Liu,Xiaojun Qu,Mingsong Zhu,Ting Huang,Qingjiang Sun
Due to their appealing properties, nanomaterials have become ideal candidates for the implementation of computing systems. Herein, an optical keypad lock based on a Förster resonance energy transfer (FRET) nanodevice is developed. The nanodevice is composed of a green-emission quantum dot with a thick silica shell (gQD@SiO2) and peripheric blue-emission quantum dots with ultrathin silica spacer (bQD@SiO2), on which 5,10,15,20-tetrakis(4-sulfophenyl)porphyrin (TSPP) is covalently linked. The nanodevice outputs dual emission-based ratiometric fluorescence, depending on the FRET efficiency of bQD–porphyrin pairs, which is highly sensitive to the metalation of TSPP: values are 59.7%, 44.8%, and 10.1% for bQD–Zn(II)TSPP, bQD–TSPP, and bQD–Fe(III)TSPP pairs, respectively. As such, by using the competitive chelation-induced transmetalation of TSPP, the nanodevice is capable of implementing a 3-input keypad lock that is unlocked only by the correct input order of Zn(II) chelator, iron ions, and UV light. Interestingly, the reversible transmetalation of TSPP permits the reset (lock) operation of the keypad lock with the correct input order of ascorbic acid, Zn(II), and UV light. Application of the nanodevice is exemplified by the construction of paper and cellular keypad locks, respectively, both of which feature signal readability and/or high resettability, showing high potential for personal information identification and bio-encryption applications.
Jiaxin Yin,Xiaoqing Huo,Xiaole Cao,Ruonan Li,Yuxuan Zhou,Tao Jiang,Longfei Wang,Zhiyi Wu,Zhong Lin Wang
Conventional electronic combination lockers are usually constructed with an active password input module, which requires the necessary electrical connections. In this work, a new passive smart electronic password locker based on photoelectric signal conversion is reported. When a ZnS-based mechanoluminescent material is subjected to an external force, the mechanical stimulus is converted into light energy. According to this light-emitting property, we developed an optical signal unit as the password input module of the password locker. Benefiting from the mechanoluminescence properties of the ZnS:Cu and randomly distributable visible light sensor, the electronic password locker key has good concealment and randomness. In addition, the surface coating treatment reduces the risk of fingerprint leakage, thus further improving the security performance of the password locker. This work broadens the application path for ZnS-based mechanoluminescence materials, which provides a novel perspective for practical applications such as a smart home.