Abstract
<title>Abstract</title> <p> The dual crises of electronic waste proliferation and inequitable access to scientific instrumentation demand transformative solutions. Here we present a low-cost, modular spectrometer constructed from repurposed DVDs (as diffraction gratings), discarded webcams (as detectors), and Lego® bricks (as reconfigurable optomechanical frames), which achieves performance comparable to commercial units (resolution Δλ ~1.24 nm; R <sup>2</sup> > 0.99 for calibrated emission lines) while reducing production costs by 99%. The system’s design leverages circular economy principles, converting e-waste into a precision tool capable of quantifying environmental contaminants. The design also supports hands-on spectroscopy education, offering a scalable model for sustainable STEM pedagogy. This work demonstrates a practical pathway to reduce e-waste and promote equitable science education through accessible, high-performance instrumentation. </p>