Circularly Polarised Luminescent Photography and Lanthanide Complexes for Advanced Intelligent Security Applications

造假对社会极为有害。认证产品和文件对全球商业、健康和个人身份至关重要。为了打击假冒，已经开发了大量的明显和隐蔽的防伪措施和技术。也许最著名的防伪标签是发光安全油墨，通常用于钞票和护照。镧系元素配合物由于其独特且稳健的物理化学性质（例如指纹状发射轮廓和长发光寿命）而广泛用于发光安全油墨中。拟议的项目将利用圆偏振发光（CPL）现象，其中相同化学实体的不同对映体产生不同的光旋向（左或右）。镧系元素复合物可以被设计成发射CPL，CPL在发光光谱中编码手性分子指纹，这些指纹不能被常规光学测量解码。然而，由于缺乏合适的手持式快速“ad-hoc”CPL检测技术，手性CPL信号尚未被开发作为高级安全油墨中的额外安全层。在过去的十年中，我们在基于镧系发光的CPL活性明亮光学探针和染料的开发中处于领先地位（道尔顿Trans.，2015，44，4791-4803）。几种Ln（III）络合物具有高的热稳定性和耐热性，具有完全的CPL指纹保留，使它们成为合适的候选物（Chem.Sci.，2018，9，1042-1049）用作隐藏变色龙安全油墨（CSI）中的额外层。CSI的联合收割机将有机短寿命（ns）绿色/蓝色发射体和手性（CPL活性）红色/绿色（铽/铕）长寿命（ms）发射体组合，嵌入透明聚合物基质中。他们铺平了道路走向多层：多色，光谱，螺旋，高空间和时间分辨率不可克隆的QR码生成与前所未有的5层“肉眼不可见”的安全性。“塑料”钞票的广泛使用有助于引入“隐藏在视线中”的CSI特征，当与正确的工具相结合时，可以促进特别验证，进一步提高安全性和真实性。2020年，我们开创性的固态CPL光谱仪（Nat. Commun.，2020，11，1676）引发了CPL光谱学的范式转变，在过去的50年里，由于其停滞不前的设计，阻碍了其使用和广泛应用，这一转变一直受到阻碍。我们的新型CPL光谱仪首次允许利用快速时间分辨CPL光谱。今年早些时候（国家通讯社，2022，13，553），我们构建并验证了世界上第一台CPL激光扫描共聚焦显微镜（CPL-LSCM），该显微镜独特地能够同时记录左手和右手CPL，允许发射手性分子的对映选择性差分手性对比（EDCC）成像，再次点燃并拓宽了CPL研究的视野。在这个项目中，我们着手将我们的专利CPL手性光学分离器单元嵌入到手持式固态CPL摄影（CPLP）相机系统中。一旦它被完全开发和验证，它可以用于“ad-hoc”时间分辨EDCC测量。这可以真正放大CPL的潜在潜力，并为新型不可克隆的发光安全油墨铺平道路。利用CPL检测迄今未开发的好处将使生命和材料科学的广泛社区采用这种简单的技术。我们预测，在全球范围内，这将带来潜在的改变游戏规则的影响，其影响将超出与该项目相关的科学效益，并可能产生巨大的商业利益。

Counterfeiting is extremely detrimental to society. Authenticating products and documents is vital to global commerce, health and personal identity. A plethora of noticeable and concealed anti-counterfeiting measures and technologies have been developed to combat counterfeiting. Perhaps the most well-known class of anti-counterfeiting labels are luminescent security inks, which are commonly applied to bank notes and passports. Lanthanide complexes are widely used in luminescent security inks due to their unique and robust photophysical properties such as fingerprintlike emission profiles and long luminescent lifetimes. The proposed project will harness the phenomenon of Circularly Polarised Luminescence (CPL), where different enantiomers of the same chemical entity produce different handedness (left or right) of light. Lanthanide complexes can be engineered to emit CPL, which encodes chiral molecular fingerprints in luminescence spectra that cannot be decoded by conventional optical measurements. However, chiral CPL signals have not yet been exploited as an extra security layer in advanced security inks due to the lack of suitable handheld rapid 'ad-hoc' CPL detection technology.Over the past decade, we have led the way in the development of CPL active bright optical probes and dyes based on lanthanide luminescence (Dalton Trans., 2015 ,44, 4791-4803). Several Ln(III) complexes possess high thermal stability and resistance, with complete CPL fingerprint preservation, making them suitable candidates (Chem. Sci., 2018, 9, 1042-1049) to be used as extra layers in hidden Chameleon Security Inks (CSI).CSI's combine organic short-lived (ns) green/blue emitters and chiral (CPL active) red/green (terbium/europium) long-lived (ms) emitters embedded into transparent polymer matrices. They pave the way towards multi-layered: multi-coloured, -spectral, -helicity, high spatial and temporal resolution unclonable QR code generation with an unprecedented 5 layers of 'invisible to the naked eye' security. The wide-spread use of 'plastic' banknotes facilitates the introduction of 'hidden in plain sight' CSI features, when combined with the right instrument can facilitate ad-hoc verification further advancing security and authenticity. In 2020 our pioneering solid-state CPL spectrometer (Nat. Commun., 2020, 11, 1676) triggered a paradigm shift in CPL spectroscopy that has been hindered over the last 50 years due to its stagnant design that prevented its use and widespread application. For the first time, our novel CPL spectrometer allowed rapid time-resolved CPL spectroscopy to be exploited. Earlier this year (Nat. Commun., 2022, 13, 553) we constructed and validated the world's first CPL Laser Scanning Confocal Microscope (CPL-LSCM), which is uniquely capable of simultaneously recording left- and right-handed CPL allowing enantioselective differential chiral contrast (EDCC) imaging of emissive chiral molecules, yet again igniting and broadening the horizon of CPL research. In this project we set out to adapt and embed our patented CPL chiroptical separator unit into a hand-held, solid-state CPL photographic (CPLP) camera system. Once it is fully developed and validated it can be used for 'ad-hoc' time-resolved EDCC measurements. This could truly amplify the underlying potential of CPL and pave the way towards novel unclonable luminescent security inks. Harnessing the so far unexploited benefits of CPL detection would allow the broad communities of life and material sciences to adopt this facile technology. We forecast a potentially game-changing impact on a global scale that reaches further than the scientific benefits associated with this project and could generate immense commercial interest.