Component reconstitution-driven photoelectrochemical sensor for sensitive detection of Cu²⁺ based on advanced CuS/CdS p-n junction

The rational design of robust photoactive material and artful sensing strategy are vital for the construction of an ultrasensitive photoelectrochemical (PEC) sensor. Although great progress has been made in PEC sensing, the resultant detection performances and adoptable sensing strategies are still limited. Herein, through the design of a subtle component reconstitution strategy, an ultrasensitive PEC sensor is developed for the detection of Cu²⁺ based on advanced CuS/CdS nanohybrids (NHs). This proposed sensor shows superior sensing performances with a low detection limit of 0.1 nM and a wide detection range from 0.2 nM to 60 µM due to the formation of p-n junction between CuS and CdS and the component transformation of CdS to Cu_xS (x = 1,2). Moreover, such PEC sensor also displays goodish results for monitoring the Cu²⁺ released from apoptotic HeLa cells in vitro. This idea of component reconstitution provides a new paradigm for the design of advanced PEC sensors.