Spectrophotometry is a fundamental analytical technique in science education. Commercial instruments are often viewed as “black boxes”, due to their ready-to-use design, limiting student understanding of operational principles. While recently reported three-dimensionally (3D) printed spectrophotometers with smartphone-based detectors offer low-cost, accessible platforms for exploring internal components, their fabrication remains time-intensive. In this paper, we present a Lego-built spectrophotometer that eliminates the need for 3D printing, while enhancing student engagement in the construction process. We provide a comprehensive overview of the design and discuss some of its inherent limitations. Student-performed quantitative analyses of blue food coloring in a sample beverage demonstrated sufficient accuracy and precision compared to those of commercial instruments for analytical applications. Post-laboratory surveys revealed that students found the Lego spectrophotometer to be an effective and engaging pedagogical tool. This work demonstrates that modular construction approaches can provide accessible, educational alternatives to both commercial and 3D-printed instrumentation in undergraduate teaching laboratories.
Chalermsongsak et al. (Thu,) studied this question.