# Covalently Modified Molecular-Recognition-Capable UV-Transparent Microplate for Ultra-High-Throughput Screening of Dissolved Zn2+ and Pb2+

## TL;DR

A new UV-transparent microplate was developed for fast and efficient detection of Zn2+ and Pb2+ in solutions.

## Contribution

A novel three-step microplate modification technique and optochemical screening method for Zn2+ and Pb2+ detection.

## Key findings

- The microplate can process over 1000 samples per hour with detection limits of 8.0 × 10−9 mol/L for Zn2+ and 3.0 × 10−8 mol/L for Pb2+.
- The method uses a covalently attached sensor molecule via photocatalytic copolymerization for high compatibility and performance.
- Only 20 µL of sample volume is required for accurate detection.

## Abstract

Zn2+ has a crucial role both in biology and the environment, while Pb2+ presents serious hazards in the same areas due to its toxicity, and the need for their analysis often exceeds available instrumental capacity. We report, herein, a new high-throughput optochemical screening method for Zn2+ and Pb2+ in various solutions. Moreover, we also introduced a new and generalizable three-step-microplate-modification technique, including plasma treating, linker-docking and photocatalytic copolymerization. The surface of a commercially available 96-well-cycloolefin-microplate was treated with atmospheric plasma, and then, the bottoms of the wells were covered by covalently attaching a methacrylate-containing linker-monolayer. Finally, the preactivated microplate wells were covalently functionalized by immobilizing bis(acridino)-crown ether-type sensor molecules, via photocatalytic copolymerization, to a polymethacrylate backbone. This sensing tool can be used in all microplate readers, is compatible with liquid handling platforms and provides an unprecedently fast monitoring (>1000 samples/hour, extrapolated from the time required for 96 measurements) of dissolved Zn2+ and Pb2+ among recent alternatives above the detection limits of 8.0 × 10−9 and 3.0 × 10−8 mol/L, respectively, while requiring a sample volume of only 20 µL.