Do sins have a smell that angels can detect, but humans cannot?

Some scholars have stated that the angel becomes aware of what is in the human heart, either by Allah informing him, or by Allah creating knowledge in him through which he perceives it. This is supported by the fact that the angel is called upon to record such and such for so and so, whereupon he says, "O Lord, he did not do it," and it is said, "Indeed, he intended it." It is also said that the angel perceives a foul odor when one intends an evil deed, and a pleasant odor when one intends a good deed. A Muslim should busy himself with what benefits him and not occupy himself with the unseen matters that the Qur'an remained silent about and that were not mentioned in the authentic Sunnah.