Spherical biosamples such as immunobeads, cells, and cell aggregates have been widely used in bioapplications. The bioactivity of individual spherical biosamples in highly sensitive assays and individual analyses must be evaluated in a high-throughput manner. Electrochemiluminescence (ECL) imaging was recently proposed for the high-throughput analysis of diffusive molecules from spherical biosamples. ECL imaging involves the placing of spherical biosamples on a flat electrode filled with a solution. The biosamples produce (or consume) biological/chemical molecules such as H₂O₂ and O₂, which diffuse to form a concentration gradient at the electrode. The ECL signals from the molecules are then measured to obtain the concentration profile, which allows the flux to be estimated, from which their bioactivities can be successfully calculated. However, no studies on theoretical approaches for spherical biosamples on flat surfaces have been conducted using ECL imaging. Therefore, this paper presents a novel spherical diffusion theory for spherical biosamples on a flat surface, which is based on the common spherical diffusion theory and was designated as the extended spherical diffusion theory. First, the concepts behind this theory are discussed. The theory is then validated by comparison with a simulated analysis. The resulting equation successfully expresses the concentration profile for the entire area. The glucose oxidase activity in the hydrogel beads is subsequently visualized using ECL imaging, and the enzymatic product flux is calculated using the proof-of-concept theory. Finally, a time-dependent simulation is conducted to fill the gap between the theoretical and experimental data. This paper presents novel guidelines for this analysis.

中文翻译：

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扩展球面扩散理论：球形生物样品中扩散分子的电化学发光成像分析


免疫珠、细胞和细胞聚集体等球形生物样品已广泛用于生物应用。在高灵敏度分析和单个分析中，必须以高通量方式评估单个球形生物样品的生物活性。最近提出了电化学发光 （ECL） 成像，用于球形生物样品中扩散分子的高通量分析。ECL 成像涉及将球形生物样品放置在充满溶液的扁平电极上。生物样品产生（或消耗）生物/化学分子，例如 H₂、O₂ 和 O₂，这些分子扩散在电极上形成浓度梯度。然后测量来自分子的 ECL 信号以获得浓度曲线，从而可以估计通量，从而成功计算它们的生物活性。然而，尚未使用 ECL 成像对平面上球形生物样品的理论方法进行研究。因此，本文提出了一种新的球形生物样品在平面上的球面扩散理论，该理论基于常见的球面扩散理论，被命名为扩展球面扩散理论。首先，讨论了该理论背后的概念。然后通过与模拟分析进行比较来验证该理论。所得方程成功地表达了整个区域的浓度分布。随后使用 ECL 成像观察水凝胶珠中的葡萄糖氧化酶活性，并使用概念验证理论计算酶促产物通量。最后，进行了瞬态仿真以填补理论和实验数据之间的空白。本文为这种分析提供了新的指南。