Ultra-Fast Laser Marking of TiO ₂ /Ti Arrays on Titanium Foils for Scalable Construction of All-Metal Light-Addressable Photoelectrochemical Sensors

This work reports a laser marking method for the scalable construction of integrated light-addressable photoelectrochemical sensors (LAPECSs), which can produce an eight-zone addressable TiO₂/Ti array on a single 1.8 cm × 4.8 cm titanium foil within 1 min using a 1064 nm laser marking machine (<$1000). The resulting TiO₂/Ti array possesses good conductivity, hydrophilicity, mechanical property, and PEC performance. Moreover, its surface can be uniformly functionalized with polyphenol dyes or functional proteins with high loading and activity by a solution incubation method. A disposable LAPECS of organophosphorus pesticides (OPs) was thus constructed using anthracene blue as the sensitizer and acetylcholinesterase (AChE) as the transducer, which allows the detection of dichlorovinyldimethyl phosphate (DDVP) with a calibration range of 10 to 250 ng mL^-1 and a detection limit of 6.1 ng mL^-1 (S/N = 3). The present work thus establishes a versatile approach to the rapid mass production of all-metal LAPECSs with high performance, high integration, and low cost.