Here we present LUCOS (Luminescent Competition Sensor), a modular and broadly applicable bioluminescent diagnostic platform enabling the detection of both small molecules and protein biomarkers. The construction of LUCOS sensors entails the covalent and site-specific coupling of a bioluminescent sensor component to an analyte-specific antibody via protein G-mediated photoconjugation. Target detection is accomplished through intramolecular competition with a tethered analyte competitor for antibody binding. We established two variants of LUCOS: an inherent ratiometric LUCOSR variant and an intensiometric LUCOSI version, which can be used for ratiometric detection upon the addition of a split calibrator luciferase. To demonstrate the versatility of the LUCOS platform, sensors were developed for the detection of the small molecule cortisol and the protein biomarker NT-proBNP. Sensors for both targets displayed analyte-dependent changes in the emission ratio and enabled detection in the micromolar concentration range (K_D,app = 16–92 μM). Furthermore, we showed that the response range of the LUCOS sensor can be adjusted by attenuating the affinity of the tethered NT-proBNP competitor, which enabled detection in the nanomolar concentration range (K_D,app = 317 ± 26 nM). Overall, the LUCOS platform offers a highly versatile and easy method to convert commercially available monoclonal antibodies into bioluminescent biosensors that provide a homogeneous alternative for the competitive immunoassay.

中文翻译：

---

将抗体转化为比率生物发光传感器，用于基于竞争的均质免疫测定

在这里，我们推出 LUCOS（发光竞争传感器），这是一种模块化且广泛适用的生物发光诊断平台，能够检测小分子和蛋白质生物标志物。 LUCOS 传感器的构建需要通过 G 蛋白介导的光共价将生物发光传感器组件与分析物特异性抗体进行共价和位点特异性偶联。目标检测是通过与束缚分析物竞争者进行分子内竞争来实现抗体结合。我们建立了 LUCOS 的两种变体：固有比率 LUCOSR 变体和强度 LUCOSI 版本，可在添加分裂校准荧光素酶后用于比率检测。为了证明 LUCOS 平台的多功能性，开发了用于检测小分子皮质醇和蛋白质生物标志物 NT-proBNP 的传感器。两个目标的传感器都显示出与分析物相关的发射比变化，并能够在微摩尔浓度范围内进行检测（K _D,app = 16–92 μM）。此外，我们还表明，可以通过减弱系留的 NT-proBNP 竞争剂的亲和力来调整 LUCOS 传感器的响应范围，从而能够在纳摩尔浓度范围内进行检测 ( K _D,app = 317 ± 26 nM)。总体而言，LUCOS 平台提供了一种高度通用且简单的方法，可将市售单克隆抗体转化为生物发光生物传感器，为竞争性免疫测定提供同质替代方案。