Portable and inexpensive analytical tools are required to monitor pharmaceutical quality in technology limited settings including low- and middle-income countries (LMICs). Whole cell yeast biosensors have the potential to help meet this need. However, most of the readouts for yeast biosensors require expensive equipment or reagents. To overcome this challenge, we have designed a yeast biosensor that produces a unique scent as a readout. This inducible scent biosensor, or “scentsor”, does not require the user to administer additional reagents for reporter development and utilizes only the user’s nose to be “read”. In this Letter, we describe a scentsor that is responsive to the hormone estradiol (E2). The best estimate threshold (BET) for E2 detection with a panel of human volunteers (n = 49) is 39 nM E2 (15 nM when “non-smellers” are excluded). This concentration of E2 is sensitive enough to detect levels of E2 that would be found in dosage forms. This paper provides evidence that scent has the potential for use in portable yeast biosensors as a readout, particularly for use in LMICs.

中文翻译：

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“Scentsor”：一种带有嗅觉报告器的全细胞酵母生物传感器，用于低成本和无设备的药物检测。

在包括低收入和中等收入国家 (LMIC) 在内的技术有限环境中，需要便携式且廉价的分析工具来监测药品质量。全细胞酵母生物传感器有可能帮助满足这一需求。然而，大多数酵母生物传感器的读数需要昂贵的设备或试剂。为了克服这一挑战，我们设计了一种酵母生物传感器，可以产生一种独特的气味作为读数。这种可诱导的气味生物传感器，或“气味器”，不需要用户管理额外的报告开发试剂，并且仅利用用户的鼻子来“读取”。在这封信中，我们描述了一种对雌二醇 (E2) 激素有反应的气味剂。一组人类志愿者进行 E2 检测的最佳估计阈值 (BET) ( n= 49) 是 39 nM E2（排除“非嗅觉者”时为 15 nM）。这种 E2 浓度足够灵敏，可以检测剂型中的 E2 水平。本文提供的证据表明，气味有可能作为读数用于便携式酵母生物传感器，特别是用于 LMIC。